TS Class 7

TS SCERT 7th Class Science Guide Telangana 15th Lesson Soil: Our Life Textbook Questions and Answers.

TS 7th Class Science 15th Lesson Questions and Answers Telangana – Soil: Our Life

Question 1.
How can you say soil is a precious resource ? Give reasons.
Answer:

• It supports the existence of living organisms.
• We can use soil for different purposes in our life.
• Almost all things in our surroundings directly or indirectly depend on soil.
• It is one of the most important natural resources.

Question 2.
Which type of soil is suitable for growing cotton ?
Answer:
Cotton is grown in sandy, loamy or black soil. Black soil is sticky in nature. It retains water for a long time.

Question 3.
Give reasons for low percolation rate of clay soil as compared to sandy soil.
Answer:

• Amount of water that passes through soil particles gives us percolation rate.
• Percolation rate is highest in the sandy soil and least in the clayey soil.

Reason : In clayey soil, the particles are very close to each other. So, its percolation rate is less. In sandy soil, the particles are at a far distance. So. its percolation rate is more.

Question 4.
Why is top soil more useful for us?
Answer:

• Soil is a good habitat of organisms.
• Germination of seeds and roots of the plants develop in these layers.
• Different types of crops will grow in these layers.
• We use some top soil for making earthern pots.

Question 5.
What types of soils are there in your village? Make a list of crops grown on these soils.
Answer:
Clayey soils are there in my village. In these soils, paddy, sugarcane and gram are grown.

Question 6.
If a farmer wants to improve water holding capacity of his sandy soil field, what will you suggest to him?
Answer:
The farmer is advised to bring the clayey soil from the village pond and spread it on sandy soil field as layer. These two soils are mixed with one another. It improves the water holding capacity.

Question 7.
Do you think rotting vegetation and animal remains are important for the soil? In what way?
Answer:

• Rotting vegetation and animal remains make up the humus, rich in fertility.
• Humus is very important in the building of soil. It supports the growth of the plants and soil organisms.
• They contain nutrients, natural manure which give good support to the growth of plants.

Question 8.
Roots of grasses hold soil particles. This conserves the
Answer:
top soil.

Question 9.
Which of the following statements is correct? Correct the wrong one.
a. Soil forms from sand.
Answer:
Wrong.
Reason : Soil is formed of rock particles and organic matter.

b. Crop rotation protects soil fertility.
Ans: Correct
Reason: Rotation of crops retains soil fertility and productivity. Conservation of soil is important factor in agriculture.

c. Clay soil can’t hold water for a long time.
Answer:
Correct
Reason : Percolation rate of clay soil is less. So, clay soil can’t hold water for a long time.
Upper layers of soil are made of rocks.
Wrong.
Reason: Upper Layers of soil consists of humus and minerals. The layers C and R Horizons are inner layers of soil which consist of regolith or bedrocks.

Question 10.
Collect soil from your school ground. fry to make a ring with that soil. Write down your observations. What type of soil is it?
Answer:
I have collected soil from my school ground and prepared a ring. It is smooth. The type of soil is clay soil.

Question 11.
Take a boiling tube. Put two spoons of soil in it. Heat it on a spirit lamp and cover it.
a. Do this experiment and write your findings.
Answer:
In this experiment, we saw moisture in the test tube.

b. Do you find any moisture in the soil?
Answer:
Yes, moisture is found in the soil.

c. How can you say that?
Answer:
The droplets of water are seen in the upper portion of the tube. Hence, we can say that moisture is present in the soil.

Question 12.
Nazmal’s grand mother said ‘Human being always depends on soil’. Is she correct ? How do you support her statement?
Answer:
Human beings always depend on soil, Nazmal’s grand mother statement is correct. Almost all the things in our surroundings directly or indirectly depend on soil. The food is obtained from plants. Plants grow in the soil. Soil is an essential component in our life. We depend on soil for house construction, making utensils and toys etc.

Question 13.
“1f you sow a seed in the soil, it will give birth to a tiny plant which grows bigger and bigger. It is the wonder of soil’ Swetha said. How do you express your appreciation of soil like Swetha?
Answer:

• Soil is the most important natural resource.
• It supports the existence of living organisms.
• It supports all plants, animals and micro organisms.
• It enables the decomposition of dead animals and fallen trees.

Question 14.
Write a dialogue between seed and soil and perform a small play using your own script.
Answer:
Soil : Seed, why you are weeping?
Seed : My mummy sent me out from the house. Now, I have no house, no food.
Soil : Will you come to my house?
Seed : Why? I am worried that I am not good.
Soil : You are good. Don’t worry.
Seed :  I am very small. I think I am useless.
Soil : Don’t think like that. Everybody has a power.
Seed : It is correct. I will also become worthy.
Soil : Come to my house and stay some days with me. Then only you can see.
Seed : Now let’s move.

Question 15.
If you have a chance to talk with a soil scientist, what questions would you like to ask him about soil?
Answer:

• How do we find the quality of the soil?
• How do we increase the quality of the soil?
• How do we find the type of soil ? What type of crops are grown?
• What are the methods to reduce the expenditure incurred on a crop?
• How can we make soil fertile using ecofreindly methods?

Question 16.
Do you find any relationship between the chapters ‘Soil’ and ‘Nutrition in plants’. What are they?
Answer:

• There is a relationship between the chapters “Soil” and “Nutrition in plants”.
• Plants get salts and minerals from the soil.
• Plants need water from the soil.
• Plants depend on soil.

TS 7th Class Science 15th Lesson Notes Soil: Our Life

• Clay – Soil from the bank of a pond is sticky and that soil is called “clay”.
• Humus – Soil formed of rock particles and organic matter is called thumusi
• Loamy – 1f the proportions of large and fine particles are present in equal, then the soil is called loamy’.
• Sandy – If the proportion of larger sized particles is more, we call the soil ‘sandy’.
• Percolation – Water passing down through the soil particles is called ‘percolation’.
• Water retention – Water holding capacity of soil is called water retention.
• Soil profile – It is a section through different layers of the soil.
• Soil fertility – It is a major factor in agriculture. Various growth substances help in development of soil fertility.
• Soil erosion – Removal of top soil by wind, water or any other means is known as ‘soil erosion’.
• Crop rotation – Change of crop after a period of time to retain soil fertility and productivity.
• Horizons – Soil is made up of distinct horizontal layers. These layers are called “horizons” is the uppermost layer of earth’s crust.

• Soil formed of rock particles and organic matter is called ‘humus’.
• Soil is a precious resource.
• Almost all living things in our surroundings directly or indirectly depend on soil.
• Making pots by using soil is called “pottery”. Potters make pots by using clay soil on a ‘pottery wheel’.
• Basing upon the size of the particles, soils are divided into 1. Sandy 2, Clay 3. Loam
• The water in the soil is called ‘percent moisture”.
• Amount of water that passes through gives us ‘percolation rate’. it is highest in the ‘sandy soil’ and least in the ‘clayey soil’.
• Soils contain minerals.
• Most of the minerals found in the soils are salts of sodium, calcium, magnesium and potassium chlorides, suiphates and carbonates.
• Some soils are acidic in nature and some of them are basic in nature.
• Soil is made up of distinct horizontal layers. These layers are called “horizons’.
• Diffrrenf layers of soil are called “soil profile”. There are six types of horizons in the soil. They are O, A, E, B, C, R.
• Soil is formed slowly as rock erodes inti tiny pieces near the Earth’s surface.
• Water holding capacity of soil depends on soil type.
• Clay and baum are suitable for growing wheat, gram and paddy. Cotton is grown in sandy loamy or black soil.
• Removal of top soil by wind, water or any other means is known as ‘soil erosion’.
• Conservation of soil is important factor in agriculture.

TS SCERT 7th Class Science Guide Telangana 14th Lesson Water: Too Little to Waste Textbook Questions and Answers.

TS 7th Class Science 14th Lesson Questions and Answers Telangana – Water: Too Little to Waste

Question 1.
Fill in the blanks and give reasons:
a. Cleaning of water is a process of removing …………………………….. (contaminants)
Reason : The impurities present in the water are contaminants. They should be removed before drinking.

b. Waste water released by houses is called ……………………….(sewage)
Reason: All the wastes released by homes.

c. Dried ……………………… is used as manure. (slugde)
Reason: Sludge contains organic matter and nutrients useful to the soil.

d. Drains get blocked by and ……………………….. (garbage, solid wastes)
Reason: Garbage, solid wastes block the free flow of drains and thus they contaminate surrounding areas.

Question 2.
What is sewage ? Explain why it is harmful to discharge untreated sewage into rivers or seas?
Answer:
Definition: All the waste water released by homes, industries, hospitals, offices and other users is collectively called sewage.

• It is harmful to discharge untreated sewage into rivers or seas.
• Because sewage is a liquid waste, which has dissolved and suspended impurities, disease causing bacteria and other microbes. These impurities are called contaminants.
• If waste water is not treated and allowed to pass as such into resources will (rivers and seas), it causes large number of diseases.
• Sewage pollutes the water and thus dreadfully damages the living kind.
• Mostly, water pollution is seen in rivers and seas in which sewage is discharged.

Question 3.
Why should not oils and fats be released in the drain ? Explain.
Answer:

• Naturally, oils and fats are undîssolved organic compounds in the water.
• When they enter drains, they convert into volatile chemicals which damage the water and thus cause water pollution.
• If that poisonous oily water enters any fresh water and fertile soil bodies, they cause pollution.
• As a result, fresh water bodies and fertile lands become useless.

Question 4.
Describe the steps involved in getting clarified water from waste water.
Answer:

• Processes involved in getting clarified water from waste water (sewage)
• Treatment of waste water involves physical, chemical and biological processes. They remove physical, chemical and biological matter that contaminates water.

Physical process:

• Waste water is passed through bar screens. Large objects like rags, sticks, cans, plastic packets etc., are romoved by this.
• Water then goes to a grit and sand removal tank. The speed of the incoming waste water is decreased to allow sand, grit and pebbles to settle down.
• A scraper is used to remove solids like feces which settle at the bottom. This is sludge.

Biological process:

• The sludge is transferred to a seperate tank where it is decomposed by anaerobic bacteria. The biogas is produced in this process.
• Air is pumped into the clarified water to help aerobic bacteria to grow.
• Bacteria consume human waste, food waste, soaps and other unwanted matter still remaining in the clarified water.
• After several hours, the suspended microbes settle at the bottom of the tank.
• The clarified water is then removed from the tank.

Chemical process: Sometimes it may he necessary to disinfect water with chemicals like chlorine and ozone before releasing it into the distribution system.

Question 5.
What is sludge ? Explain how it is treated.
Answer:
Definition: Sludge is a solid particulate matter which separates from clarified water and settles at the bottom of the tank in sewage water treatment.

Sludge is treated by the following ways.

• Solids like faeces (sludge) is seperated and removed with a scraper.
• A skimmer also used to remove the floatable solids like oil and grease from the clarified water in order to treat the sludge.
• The sludge is transferred to a separate tank where it is decomposed by anaerobic bacteria.
• After several hours, the suspended microbes settle at the bottom of the tank as activated sludge.
• The water is then removed from the top of the tank.
• The activated sludge is about 97% water.
  The water from the sludge is removed by sand drying beds or machines.
  Dried sludge is used as manure, returning organic matter and nutrients to the soil.

Question 6.
Untreated human excreta is a health hazard. Explain.
Answer:
Untreated human excreta is a health hazard.
Excreta is one of the organic impurities.

Reason:

• Human defecated matter consists of several microbes which cause diseases.
• When man consumes food, several microbes enter into his body along with food.
• Not only disease causing organisms, but also nitrogenous and carbonic compounds present in the human excreta.
• Sometimes excreta causes air pollution, soil pollution and water pollution.
• Defecated excreta releases poisonous odour into the air and thus it causes air pollution.
• Sometimes, concentrated chemicals present in the excreta add to soil and damage the fertility of the soil and cause soil pollution
• During rainy season, open defecation leads to water pollution. Defecated matter flows along with rain water into water bodies.

Steps to treat the excreta into unpolluted substance:

• Now a days, wastage treatment plants are installed in so many areas
• They convert the excreta into useful biofertilizers.
• The treatment plants extract biogas from the excreta which is valuable for domestic as well as commercial purposes.

Question 7.
Name two chemicals used to disinfect the water.
Answer:
There are two important chemicals which disinfect water.

• Chlorine
• Ozone

These two disinfectants are added to the clarified water before releasing into the distribution system.

Question 8.
Explain the function of bar screens in a waste water treatment plant.
Answer:

• Bar screens are the special tools which remove the large objects like rags, sticks, cans, plastic packets etc., from sewage (waste water)
• They play a major role in treatment of waste water (sewage).
• They are made by iron bars which are strongly fixed in the frame at the entrance of the drain.
  These bar screens are used in the physical process of first stage of sewage treatment.

Question 9.
Explain the relationship between sanitation and disease.
Answer:

• Collecting and removal of wastes and garbage from our surroundings is collectively called as sanitation.
• Disease is nothing but any disturbance in functioning of our body parts. If we don’t maintain proper sanitation, we get diseases.
• Because wastes and garbage spread the microbes which cause many diseases.
• The best way is maintaining proper sanitation which keeps us away from the diseases.
• The more we keep our surroundings clean, the more we maintain good health.
• Hence, there is a relationship between sanitation and disease.

Question 10.
Outline your role as an active citizen in relation to sanitation.
Answer:
‘HEALTH IS WEALTH”
“CLEAN THE SURROUNDINGS – SAVE THE ENVIRONMENT”
I emphasize the above two quotes for better environment. As a citizen, I play a key role in maintaining perfect sanitation by the following ways.

• I convey all my neighbours to use public dustbins.
• I can insist the importance of bio-fertilizers which can be made easily with kitchen wastes (vegetable, rice, fruits and dal wastes).
• I can see that the bathroom and lavatory waste water should drain into under ground drainage.
• If drainage is over-flowing in my house surroundings, I can immediately complain to concerned sanitation department.
• It is my duty to keep my house always clean and tidy.
• I can make small drainage to send the used water from taps and wells to kitchen garden.
• I convey all my neighbours in residence colony not to throw the dust everywhere.
• It is important to make an arrangement for preventing stagnance of used water from our kitchens and bathrooms.
• I should see the prevention of stagnant water around public or panchayat taps and wells.
• I feel much responsibility to motivate the people about perfect sanitation to keep good health in the society.

Question 11.
What would you do to motivate people in your street to utilize toilets?
Answer:
I can motivate the people in my street to utilize toilets by the following way.

• It will be announced about occurrence of health hazards due to open defecation.
• Therefore I have to educate the people to stop such an unhygienic activity.
• I can lodge a complaint to the local government departments (sanitation departments) to construct public toilets in few places in our area.
• I can convey the people that only open defecation leads rapid spreading of dreadful diseases from one area to the other area.
• I have to educate the people about the diseases such as Typhoid. TB. Amoebiasis, Cholera and Diarrhoea which are caused and spread by open defecation.

Question 12.
What would happen if there were no microbes that break down wastes in sewage?
Answer:

• If there were no microbes that break down wastes in sewage, it will be fatal to the environment.
• The sludge formed from sewage will be decomposed by anaerobic bacteria and produce bio-gas which is used as fuel.
• If anaerobic bacteria are absent in the environment, the world would have been occupied by huge amount of sewage and sludge.
• If the sewage is not decomposed by microbes, suspended impurities would cause lot of pollution.
• Disease causing bacteria and other microbes would affect human lives and other animals.
• Totally, the entire living kingdom and the nature would have been collapsed by stagnance of sewage due to absence of decomposers (microbes).
• Hence, microbes or decomposers are the natural scavengers of the earth which remove volatile and polluted substances from the sewage.

Question 13.
What point would you like to address in the letter for your panchayat officer about drainage system in your village/town?
Answer:
I would like to address the following things in my letter to panchayat officer.

• Construction of closed drainage system to prevent air, water and soil pollution.
• To emphasize the maintenance of closed drainage system in order to prevent cause and spreading of diseases.
• To convey the development of ecofriendly environment.
• To request them to make arrangements for continuous flow of drain from panchayat taps and wells to drainages.

Question 14.
Go to nearby railway station / bus station / hospital I industry. What type of sewage is released ? List out where and how.
Answer:
Aim of the project: To list out the various types of sewage that are released from different places such as railway station, bus station, hospital and industries.
Process: I visited the following places and found the different types of sewages which are released from them.

Question 16.
Prepare atleast 5 slogans on ‘Don’t waste water”.
Answer:
Slogans on “Don’t waste water”:

• Save water – Save lives
• Water is an important matter – Keep it as an important factor.
• Every water drop counts us our lives.
• Don’t waste water – Don’t taste bitter.
• Water is valuable – Our lives are possible.

Question 17.
Make a write-up for your project on preservation of rain water.
Answer:
Aim : To construct a water shed (Inkudu gunta) in my house.

Procedure: I selected a low lying area of one of my house corners. I dug a pit upto 5 feet depth. This was done in the second week of June. Naturally, rainy season starts in the month of June.

Observation : Inkudu gunta was getting filled up with rain water in the rainy season.

Result : Our surroundings can retain and raise the ground water level. This ground water is highly useful for wells and bores, mainly for growth of plants.

Question 18.
Is there a check darn or any other water conservation unit in your village? Write a note on it.
Answer:

• There is a water conservation unit in my village called fresh water tank or reservoir.
• It is maintained by village panchayat department. The water reservoir is protected from animals, unhygienic habits of villagers.
• Besides that, there is an aerated tank, a chlorinated tank and one over-head tank.
• The villagers are depending on the water tank for drinking purposes.
• The tap water is arranged from over-head tank to all the villagers.
• All the villagers are aware of using fresh water from that water reservoir.

Question 19.
Have you got any doubts about diseases caused by untreated water? List them out.
Answer:
I doubted about some diseases caused by untreated water. They are

• Cholera
• Amoebiasis
• Diarrhoea
• Tuberculosis
• Jaundice
• Typhoid

Question 20.
If you see water running off from a public tap, what would you do about it?
Answer:

• If see water running off from a public tap, immediately I will rush to the place and close it.
• If it is still not properly closed, I can try to repair it immediately.
• Otherwise, I can complain to concerned department.
• I can advise the people to use the water judiciously.
• It is to be advised that the tap should be operated properly.

TS 7th Class Science 14th Lesson Notes Water: Too Little to Waste

• Sewage : Sewage is a liquid waste. Most of it is water, which has dissolved and suspended impurities, disease causing bacteria and other microbes.
• Sewage water : Waste water containing inorganic, organic and bacterial as well as other microbial contaminants.
• Contaminants : Unnecessary substances present in water which are harmful.
• Septic tank : The tank into which the excreta is sent.
• Drainage system : The system through which we send waste waters.
• Percolation tank : The tank in which sewage filters.
• Contour trenches : The area in which the rain water is harvested.
• Bar screen : The screen which removes large objects from sewage.
• Grit : This helps in filtration of water.
• Rock fill dam and Check dam : The dams constructed to conserve water to revive forest area.
• Activated sludge: The sludge is 97% of manure.
• Only one percent of all water resources available is fresh water.

• The available resource of fresh water is getting depleted at a very fast pace due to different human activities.
• Waste wafer is generated at homes, industries etc., by different human activities.
• All the waste water released by home, industries, hospitals, offices and other users are collectively called sewage.
• Sewage: Sewage is a liquid waste. Most of it is water, which lias dissolved and suspended impurities, disease causing bacteria and other microbes.
• Sewage water: Sewage water contains inorganic, organic and bacterial as well as other microbial contaminants.
• Waste water is treated in treatment plants.
• Physical, chemical and biological processes are involved in treatment of waste water at the treatment plants.
• Chlorine kills harm lid disease-causing organisms present in waste water.
• Aeration allows growth of microbes that break down wastes.
• Different types of drainage systems are open, closed and underground types.
• Septic tanks also help in wastewater disposal.
• Water should be treated before being released to water supply.
• Water must be conserved by individual efforts as well as through efforts made by the community.

TS SCERT 7th Class Science Guide Telangana 13th Lesson Seed Dispersal Textbook Questions and Answers.

TS 7th Class Science 13th Lesson Questions and Answers Telangana – Seed Dispersal

Question 1.
What happens if seeds are not dispersed?
Answer:

• If the seeds are not dispersed, they fall in the same place, germinate and produce new plants.
• Therefore, they do not have sufficient place to grow.
• They do not get sufficient sunlight and water.
• They cannot survive in the absence of sunlight and water.
• Finally they of will die.

Question 2.
How are the seeds dispersed in calotropis?
Answer:

• The seeds of calotropis have light and hairy structure at one end.
• They travel with wind and settle at a suitable place to germinate.
• The hairy Out growths of the seeds help in dispersal.

Question 3.
Why do most of the coconut trees grow along the sea shores ?
Answer:

• The outer covering of the coconut seed has empty spaces filled with air and some are fibrous with air spaces that enclose the whole seed or fruit.
• The entire coconut fruit floats on water and moves from one place to another.
• When it reaches the ground (sea shore). it germinates.
• That’s why we usually find coconut trees growing near sea shores.

Question 4.
Do you find any relationship between the weight of the seeds and the dispersal mechanism? Discuss with suitable examples.
Answer:
We find a relationship between the weight of the seeds and the dispersal mechanism.

• Seeds that are dispersed through air are usually light and are either very small with wings on them or some hairy structures on them.
• The seeds get adapted in such a way that they get carried away easily by wind.
  Eg: Maple, Milkweed.
• Seeds that are heavy usually go to the bottom of water sources and get carried by the flow of water.
  Eg: Seeds of lot us.

Question 5.
Ravali said “Dispersal of seed is very important in nature”. Is she correct? Why do you support her?
Answer:
I can support Ravalis opinion on importance of dispersal of seeds.
The following reasons make us believe in seed dispersal.

• To avoid competition with the mother plant for air, water and minerals, plants disperse their seeds to different distances.
• Seed dispersal is essential for survival of plants.
• Seed dispersal made easier spreading of some plant species in some larger new regions of the world.

Question 6.
Collect the information in the following table and discuss the reasons?
Answer:

Agents of dispersal	Name of the seed/fruit
By wind By water By animal By bird By man By any other	Milkweed, Maple Lotus Nuts Neem Sugar cane, Guava, Pear. Wheat, Pulses

Dispersal of seeds by wind: In plants like maple, seeds have wings Like out growths. These type of specialized structures, present in the seeds, will be helpful for dispersal by air.

Dispersal of seeds by water: Seeds of lotus that are heavy usually fall to the bottom of water and carried by the flow of water.

Dispersal of seeds by animal : Squirrel hardly eats all of hidden seeds and even forgets where it has hidden them. Thus, we have several nut trees at different places.

Dispersal of seeds by bird: Crows eat neem fruits. The outer fleshy part gets digested in the food canal and the seed coats of them become tender. They are then dispersed to other places as bird droppings.

Seed dispersal by man: European traders came to India. They left the seeds of guava, pear. India’s sugar cane is used worldwide for production of sugar.

Seed dispersal by any other: Wheat, pulses are dispersed through travelling by aeroplanes and ships.

Question 7.
Some seeds like soap nuts have very hard shell. Why is it so?
Answer:

• Some seeds like soap nuts have very hard shell.
• Because when seeds are in unfavourable or adverse atmospheric conditions, the shell or seed coat protects the seed from such a condition.
• If the seeds come in contact with water and necessary nutrient soil, they germinate.

Question 8.
Now-a-days people want to eat sprouts. List out the reasons why they take sprouts as food ?
Answer:
Now-a-days people want to eat sprouts Due to following important reasons.

• Germinating seeds or sprouts exhibit more metabolic rate.
• When the sprouts come in contact with water, the inactive enzymes present in them become more active.
• As a result, active enzymes in the sprouts are easily absorbed by our digestive system.
• Our body can receive some hormones and vitamins along with enzymes easily from the germinating seeds or sprouts.
• We can digest the sprouts very easily. Proteins and minerals in the sprouts will be absorbed by our body easily than unsprouted seeds.

Question 9.
Collect some seeds, sow them in a particular place in your school garden. Observe how many days each type of seed takes to germinate. Tabulate your observation.
Answer:
Aim : To examine the duration of germination of seeds of different plant species.

Requirements: Seeds of green gram, beans, ground nut, black gram, coriander. fertile soil, small earthen tubs, and water.

Process : I along with my classmates collected required seeds which are easily available.
They are sown in the fertile wet soil of five earthen pots.
They are kept undisturbed in open air.

Observation : It is observed that those seeds of different plants germinated in different days.

The observations are taken as below.

S.No	Seeds	The time taken for seed germination No. of days
1.	Green gram	Four days
2.	Coriander	Three days
3.	Black gram	Four days
4.	Beans	Five days
5.	Ground nut	Five days

Question 10.
Collect Tadi seeds and make a model. Display them in your school.
Answer:

• The hard shelled seeds displayed here are taken from palm trees. We call them ladi chettu’.
• Naturally, the fruits develop in the tree during summer season.
• They ripen by the month of June or July.
• The ripened fruits are very tasty. The seeds have enormous fibrous hair.
• Man and animals like pigs are responsible for dispersal of these tadi seeds.

• The hard shelled seeds displayed here are taken from palm trees. We call them ‘Tadi chettu’.
• Naturally, the fruits develop in the tree during summer season.
• They ripen by the month of June or July.
• The ripened fruits are very tasty. The seeds have enormous fibrous hair.
• Man and animals like pigs are responsible for dispersal of these tadi seeds.

TS 7th Class Science 13th Lesson Notes Seed Dispersal

• Dispersal of seeds : Seeds are carried from one place to another so that they get suitable conditions to grow. This is called dispersal of seeds.
• Bursting mechanism : Encapsulated seeds are burst by touching and uncoiling.
• Fleshy fruit : The fleshy part of the fruit enclosed in a fruit coat. Eg: Apple, Banana.
• Most of the seeds fall on the soil and get buried in flu’ ground. After sometime, they germinate and grozi’ into small plants.
• Seed dispersal is essential for survival of plants.
• To avoid competition with the mother plant for air, water and minerals, plants disperse their seeds to different distances.

• Seeds are of different shapes and sizes and structures on them help in dispersal.
• Seeds are dispersed by wind, waters, birds and animals.
• Some seeds are light in weight. They travel with wind and settle at a suitable place to germinate.
• The seeds adapted to float on water are usually light.
• Seeds that are heavy usually fall to the bottom of water sources and get carried by the flow of water. Eg : Seeds of lotus.
• Seeds are dispersed by animals in many ways.
• Some seeds get dispersed through animal excretions.
• Some seeds grow in capsules which when touched burst and uncoil with a force in such a way that they scatter the seeds all around.
• All the seeds of a fruit should be able to germinate to produce new plant.

TS Board Telangana SCERT 7th Class Science Solutions 12th Lesson Reproduction in Plants Textbook Questions and Answers.

TS 7th Class Science 12th Lesson Questions and Answers Telangana – Reproduction in Plants

Question 1.
Do all flowers have same parts? Classify the flowers according to the parts of flower present in them and give examples.
Answer:
All the flowers do not have same parts.
Based on the presence of number of parts, flowers are classified into two types.

• Complete flowers.
• Incomplete flowers.

Complete flowers : A flower that has four or more whorls – atleast one each of calyx, corolla, androecium, and gynoecium is called a complete flower. Eg: Datura, ipomoea, hibiscus.

Incomplete flowers : A flower in which any of these four whorls are missing is an incomplete flower.
Eg: Cucumber, bottle gourd, papaya.

Based on the presence of reproductive organs, flowers are classified into two types. They are

• Unisexual flowers.
• Bisexual flowers.

i. Unisexual flowers : A flower which has either stamens (androecium) or pistil (gynoecium) is called unisexual flower.
Eg: Cucumber, bottle gourd, bitter gourd.

ii. Bisexual flowers : A flower that has both stamens (androecium) and pistil (gynoecium) is called bisexual flower.
Eg : Datura, hibiscus, ipomea.

Question 2.
Differentiate between
a. bisexual flowers, unisexual flowers
b. complete flowers, incomplete flowers
c. male flower, female flower
d. sexual reproduction, asexual reproduction
e. self pollination, cross pollination
Answer:
a.

Bisexual flowers	Unisexual flowers
Both androecium and gynoecium are seen in the same flower.	Either gynoecium or androecium is seen in the flowers.
Eg : Datura, hibiscus	Eg : Cucumber, bottle gourd.

b.

Complete flowers	Incomplete flowers
Flower has four whorls at least one each of calyx, corolla, androecium and gynoecium. Eg : Datura, hibiscus.	A flower in which any of these four whorls is missing is an incomplete flower Eg : Cucumber, bottle gourd.

c.

Male flower	Female flower
Flower that possesses androecium (stamens) is called male flower.	Flower that posseses gynoecium (pistil) is called female flower.

d.

Sexual reproduction	Asexual reproduction
1. Involves one or two organisims.	1. Involves a single organism
2. Male and female reproducing cells are formed. Eg : Datura – flower.	2. No formation of reproducing cells. Eg : Ranapala – leaf.

e.

Self pollination	Cross pollination
1. Fusion of male and female reproducing cells in the same plant come together. (or) Transfer of pollen grains within the flower is known as self pollination.	1. Male reproducing cells of one plant combine with female reproducing cells of another plant of same race. (or) Transfer of pollen grain from anther of one flower to stigma of another flower of same species is known as cross pollination.

Question 3.
What happens when a pollen grain falls on stigma?
Answer:

• When pollen grain falls on the stigma, germination occurs.
• There are some substances present on the stigma which promote the germination of the pollen grains.
• During germination, a tube grows from the pollen grain. It is called pollen tube.
• This tube ultimately reaches the ovary through the style with the male part.
• This male part fuses with the female part in the ovule of the ovary.
• The fusion of male and female parts to form a structure called as zygote. This is called “Fertilization’.

Question 4.
What helps to bring pollen grains to the stigma?
Answer:
Air, watel, animals, insects, humans act as agents of pollination.
They carry pollen grains from anther to the stigma.

• Pollination by air : Pollen grains of some plants are light and small. They are easily carried by wind. They reach the stigma of the ovary. Eg : Paddy (rice), wheat etc.
• Pollination by water: In water plants, drifting of pollen grains on the surface of water helps in coming contact with the stigmas of female flowers. Eg : Vallisneria.
• Pollination by animals: The animals which bring about pollination are birds, slugs, snails, squirrels and bats.
• Pollination by insects : The pollen grains get attached to the body of the insects when they visit the flowers for food. When such insect visits another flower, pollen grains are transferred to the stigma of that flower.
  Eg: Butterflies, honey bees etc.

Question 5.
Explain the method of sexual reproduction in the plants.
Answer:

• In the flowering plants, pollination is the first step in the process of sexual reproduction that leads to the formation of seeds.
• When the pollen reaches the stigma of a flower, a fine tube-like structure is grown from the pollen grain called the pollen – tube.
• This tube passes through the style and reaches the ovules of the ovary. Ovules have a opening called micropyle.
• At the end of the pollen tube, there are two nuclei-tube nucleus and generative nucleus.
• The generative nucleus divides and forms two male nuclei while the tube nucleus disappears.
• Ovules in the ovary are developed into embryo-sac in which two nuclei are present. One is egg nucleus and the other is secondary nucleus.
• When the pollen tube breaks its tip, one of the male reproductive nuclei fuses with the egg forming a zygote. The zygote develops into embryo.
• The other nucleus of the pollen tube fuses with the secondary nucleus of the ovum and grows into endosperm. The endosperm contains reserve food material.
• The embryo finally develops into seeds.

Question 6.
Can plants produce new plants even without seeds? Explain the methods with examples.
Answer:
Plants can produce new plants even without seeds by the process of vegetative reproduction.
Definition: Production of new plants from vegetative parts of a plant i.e., root, stern and leaf is known as vegetative reproduction.

Methods of vegetative propagation:

• Vegetative propagation through roots: When the roots are cut and sown in the soil, they produce new plants.
  Eg : Curry leaf, neem, carrot, radish.
• Vegetative propagation by stems: In sorne plants, the stern grows under the ground. So, it is modified underground stem. When cut into pieces and put in the soil they give rise to new plants. Eg: Potato, ginger, hules, garlic.
• Vegetative propagation through leaves: In some plants, buds arise from the leaves. These buds drop off from the leaf and grow into new plants. Eg: Bryophyllum, begonia.
• Vegetative propagation through nodes: In some plants, we find a bunch of roots at each node. If part of the stern of such a plant along with roots is cut and planted in the soil, it grows into a new plant. Eg : Grass, sugarcane.
• Vegetative propagation through suckers: Buds sprout from the stems are called sword suckers. Stem creeps along the ground and strikes roots at the nodes. Eg : Mint, chrysanthemum, raspberry.
• Artificial methods of vegetative propagation: Ornamental and fruit yielding plants are propagated artificially.

The methods of propagation are:

• Cutting : A mature part in stem is cut-off from the plant and is put in
  the moist soil. It grows into a new plant. Eg: Rose, hibiscus.
• Layering : The lower branch will be bent and fixed in the ground. It develops roots and leaves. Eg: Rose, jasmine, croton.
• Grafting: Branch of one plant is attached to the stem of a plant of the same Species. Eg; Sapota, mango.

Question 7.
Draw the diagram of any flower showing its parts.
Answer:

Question 8.
Do all plants reproduce in the same way? Explain with examples.
Answer:
All plants do not reproduce in the same way.
1. In flowering plants, sexual reproduction is the most common method. It is clone by floral reproducing parts. Eg: Datura.
2. In lower organisms, asexual reproduction is more common. This occurs in different ways in different organisms.

• Asexual reproduction takes place by means of spores. Eg : Spores of fungi (rTìucor, aspergillus).
• Asexual reproduction takes place by means of budding. Eg : Yeast.
• Asexual reproduction takes place by means of sporulation and fragmentation. Eg : Mucor.

Spores are the common reproducing cells in fungi. When they come in contact with suitable atmospheric conditions, they develop into new organisms. But in some higher plants, vegetative parts such as roots, stems and leaves produce new plants. This is simple method of reproduction. Eg : Jasmine, rose, potato, ginger etc.

Question 9.
Karthik saw a cucumber plant in the kitchen garden. He identified two types of flowers – some flowers had a small swollen structure behind them while some did not. He removed all the flowers which did not have the swollen structure behind them thinking that they were of no use. Which flowers did he remove? What are the flowers which had a small fruit behind them?
Answer:

• Karthik had an idea of sexual reproduction in the plants.
• First he observed all the flowers whether they performed fertilization in them or not.
• He had a keen observation on reproductive parts of flowers.
• The flowers which exhibit reproduction will have swollen thalamus region. Above this thalamus, ovules develop into seeds that are commonly called the ovary of the female part.
• If fertilization is done in the ovules of the ovary, embryos develop into seeds and other parts of the ovary develops into fruit flesh. As a result, the basal part of the flower looks swollen above the thalamus region.
• Therefore, Karthik concluded that swollen parts of flowers are nothing but immature fruit structures. They are retained by him on the plant.
• The flower without swollen parts behind them are unfertilized flowers. They are removed by him from the plant.

Question 10.
What are the agents of pollination?
Answer:
Water, wind, animals, birds, insects etc are the agents of pollination.

Question 11.
Differentiate between self pollination and cross pollination.
Answer:

Self pollination	Cross pollination
1. Pollen grains of a flower are transferred to the stigma of the same flower.	1. Pollen grains of one flower are carried to the stigma of another flower of same plant or a different plant of the same species.
2. Only one parent is involved in sexual reproduction.	2. Single parent plant or two different plants of same species are involved
3. Less chance of appearance of more new characters in the off-spring.	3. More chances of appearance of more new characters in the off spring.
4. This is naturally done in bisexual flowers.	4. This is naturally done in sexual flowers as well as sometimes in bisexual flowers.
5. The seeds are less in healthy condition. Eg : Wheat, peas, datura.	5. The seeds are more in healthy condition. Eg : Hibiscus, brinjal, tomato.

Question 12.
Name the parts of the following plants from which they propagate vegetatively.
a) Potato
b) Bryophyllum.
Answer:
a. In potato tuber sunken spots have small centres which have the capacity to give rise to a whole plant. The shape of these structures is similar to eye and are called eyes of potato.
b. In bryophyllurn, leaf is broad and has notches at its margins. Buds arise from these notches. They develop into a new plant.

Question 13.
What am I?
a. I am formed by the fusion of male and female parts.
b. I am a part of the plant that can travel a long distance and grow to a  baby plant.
Answer:
a. Zygote is formed by the fusion of male and female gamete.
b. Seed is a part of the plant that can travel a long distance and grow to a baby plant.

Question 14.
Fill in the blanks :
a. Flowers containing both male and female parts are called …………………… (bisexual flowers)
b. Pollen grain from the anther of one flower that reaches the stigma of another flower is called ………………(cross-pollination)
c. From ……………… part of Bryophylluin, new plants are produced. (leaf)
d. Agents of pollination are and insects. (air, wind, animals)
e. Transfer of pollen grain from anther to stigma is called (pollination)
Answer:
a. bisexual flowers
b. cross-pollination
c. leaf
d. air, wind, animals
e pollination

Question 15.
Match the following:
A —- B
1. Pollengrairi — ( C ) A) Ovary
2. Ovule — ( A ) B) Bryophyllum
3. Reproduction through eyes — ( D ) C) Anther
4. Reproduction through leaves —  ( B ) D) Potato
Answer:
1 – C ,2 – A , 3 – D, 4 – B

Question 16.
Observe the following figures. What difference do you observe. Write in your notebook.
Answer:
i. Diagram:
In the first diagram the arrow mark on the flower shows transfer of pollen grains from the anther to the stigma of gynoecium (pistil) of the same flower.

ii. The flower exhibits self pollination. Because both male and female reproductive organs are present in the same flower.
reproductive organs are present in the same flower.

(ii) and (iii) Diagrams:
In the second and third diagrams, the arrow mark shows cross pollination. Transfer of pollen grains from second flower is carried to the stigma of the another flower. Though the flowers are having both the male and female reproductive parts, they tend to show cross pollination.

TS 7th Class Science 12th Lesson Notes Reproduction in Plants

• Cutting : This is an artificial mode of vegetative propagation.
• Androecium : The soft elongated structures attached to petals are stamens. The stamens are together called androecium.
• Gynoecium : Female reproductive part of the flowers.
• Thalamus : The stalk of the flower has a slightly swollen head. It is called “thalamus”.
• Corolla : The third attractive coloured whorl of the flower is called corolla.
• Calyx : The green tube like structure around the flower is called calyx.
• Stamen : The male reproductive part of the flower.
• Pistil : Gvnoecium is otherwise called as pistil.
• Anther : The part of the stamen with pollen.
• Filament : Stalk of the stamen.
• Budding : A type of asexual reproduction.
• Zygote : The cell developed from fusion of two reproductive cells.
• Vegetative propagation : Asexual reproduction occurs in plants by vegetative parts like stem, root, leaf etc.
• Spore : Asexual reproducing cell seen in lower plants.
• Pollination : Transfer of pollen from anther of the stamen to stigma of ovary.
• Fertilization : Fusion of male and female parts to form zygote is called Fertilization.
• Theophrastus, a Greek philosopher and the pupil of Aristotle, is known as the father of Botany. Reproduction in plants was first studied in detail by Theophrastus.

• Flowers are the most attractive parts of any plant.
• The flower represents the sexual reproduction in the plants.
• Thalamus : The stalk of the flower has a slightly swollen head called ‘thalamus”.
• Calyx: The green tube like structure around the flower is called calyx.
• The calyx consists thin leaf like structures called sepals.
• Funnel shaped structures inside the calyx are called corolla, This is fonned offered petals.
• There are soft elongated structures attached to petals, called stamens. The stamens are together called androecium.
• As we remove petals, right on the thalamus is seated a bulb like structure called ovary. Just above it, a fine tube like structure called style is present. The style ends with stigma.
• Based on presence and absence offloral parts, flowers are two types-complete flowers and incomplete flowers.
• Based on presence of sexual parts, flowers are of two types-bi sexual flowers and unisexual flowers.
• Transfer of pollen grains from anther to stigma is called as pollination. Flowers can be self pollinated or cross pollinated.
• Fusion of male and female parts foforin zygote is called Fertilization.
• On the basis of parts involved, reproduction in plants is of two types, sexual reproduction and asexual reproduction.
• Production of offspring from zygote is called sexual reproduction.
• Formation of new plants without sexual reproduction is asexual reproduction.
• Vegetative propagation : Asexual reproduction occurs in plants by vegetative parts like stem, root, leaf etc.

 

TS Board Telangana SCERT 7th Class Science Solutions  11th Lesson Respiration in Organisms Textbook Questions and Answers.

TS 7th Class Science 11th Lesson Questions and Answers Telangana – Respiration in Organisms

Question 1.
Fill in the blanks and give reasons:

1. ……………. are the respiratory organs of fish. (Gills)
Reason : Aquatic animals like fish possess gills for respiration. They are modified naturally to obtain dissolved oxygen from the water.

2. In a cockroach, a network of ………………….. is found.
(respiratory tubes called trachea)
Reason : Cockroach has only air tubes or trachea to breathe oxygen directly from the air. Trachea send the oxygen to each and every cell.

3. ……………… are found on leaves for the exchange of gases. (Stomata)
Reason: Stomatal openings in leaves regulate the gaseous exchange. They take plenty of carbon dioxide and release oxygen. They also help in respiration.

Question 2.
What is respiration ? How is it different from breathing?
Answer:
Definition: Burning (oxidation) of food material especially glucose, fatty acids and proteins to carbon dioxide and water is called respiration.
Difference between respiration and breathing : Breathing is a process of taking of air into our body and leaving out air from our body. Breathing exhibits a mechanism of two steps. They are

• Inspiration
• Expiration

Respiration exhibits a mechanism inside the respiratory organs and at cellular levels.
Respiration rate depends on the number of times we breathe in and breathe out air in a minute.

Question 3.
Frogs breathe through their skin as well as their lungs. Explain.
Answer:

• Frog is an amphibious animal lives in water and on land.
• In frog, skin is a very important respiratory organ in both on land (in burrows) and water.
• One third of the total oxygen taken up by frog is through the skin.
• To breathe on land it has lungs. When it goes deep underground and sleeps twice every year, it depends on skin for respiration.
• Its moist skin takes over the function of its lungs.

Question 4.
If you want to know about “Actions of gases in lungs what questions you would like to ask?
Answer:
If I want to know about “Actions of gases in lungs” I can ask the following questions.

• How do lungs receive gases during respiration?
• What gases do they receive ?
• How can lungs react to the gases which enter in?
• Explain the mechanism of respiration in lungs filled with gases.

Question 5.
If you did this experiment of respiration with fruits and dry leaves, what would the result be? Explain. (Experimentation and Field Investigation)
Answer:

• A glass jar is taken.
• A ripening fruit is kept inside the jar along with a small beaker of lime water.
• The jar is closed with rubber cork and kept under observation.
• After a few hours the lime water turns into milky white.
• It is because of CO₂ released by ripening fruit during the process of respiration.
• We cannot observe any colour change in lime water when the same experiment is done with dry leaves.
• Because dry leaves do not perform respiration and release CO₂
• They are dead.

Question 6.
It is very interesting to watch fish in an acquarium. Make your own bottle aquarium. (Information Skills and Projects)
Answer:
Aim : To make a bottle aquarium in the class room.

Apparatus : Wide mouthed glass bottle (empty horlicks bottle), water, 5 small fishes, pebbles. small water plants.

Procedure :

• A wide mouthed glass bottle is taken and is filled with water.
• Certain amount of pebbles and small water plants are placed in the bottle.
• Finally five collected fishes are introduced into the bottle.
• Bottle acquarium is ready.

Question 7.
Do you find any relation between plants and animals by their respiration and photosynthesis?
Answer:

• Plants perform photosynthesis as well as respiration whereas animals never perform photosynthesis but they perform only respiration.
• We cannot recognise the external respiration in plants. Higher animals have external respiration and internal respiration.
• In animals respiration is done by special organs.
• There are no special organs of respiration in plants.

Question 8.
Asif wondered how plants and animals which live under water also respire. Do you know how? (Appreciation and Aesthetic Sense and Values)
Answer:

• Everyone wonders at the living organisms which lives in water.
• The plants and animals which live under water take oxygen that is dissolved in water.
• So, dissolved oxygen is essential for respiration for aquatic plants and animals.
• When aquatic organisms respire they obtain oxygen from water and release carbon dioxide into water. The released carbon dioxide dissolves in the water.

Question 9.
Imagine the size of the lungs in elephant. Is there any relation between body size and lung size ? Collect information from school library or internet.
Answer:

• As the elephant’s body is large in nature its size of lungs is also naturally large.
• The volume of the lungs depends on the size for the body of an organism.
• It is because to meet the demand of oxygen supply for the entire organism.
• The lungs of an elephant are more elastic also. They can accommodate 310 litres of air for one breath.
• When we look at the rat or mouse, their body size is small and their lungs are also naturally small.
• They do respire with their small lungs to meet the demand of needed oxygen for their body.
• Hence there is a relation between body size and lungs’ size. The lungs size is always proportionate to the size of the body.

TS 7th Class Science 11th Lesson Notes Respiration in Organisms

• Spiracle : Openings which allow air into the body of insect.
• Gills : Respiratory organs in fish and tadpole larva of frog.
• Carbondioxide : The gas useful for plants for preparing food.
• Oxygen : The gas essential for animals for breathing.
• Inhale : Taking of air inside the body.
• Exhale : Leaving of air outside the body.
• Exhale : Leaving of air outside the body.
• Inspiration & Expiration: The process of breathing in air is called inspiration and that of breathing out air is called expiration.
• Trachea : Respiratory tubes in insects.
• The process by which air goes in and out of our body is called breathing.
• The process of breathing in air is called inspiration and that of breathing out air is called expiration.
• The number of things we breath in and breathe out air in a minute is called the respiration rate.
• The air we breathe in, fills our lungs that are located in our chest.
• The first step towards trying to find out what air contained was carried out by Von Helniont.
• Joseph Priestly discovered the presence of oxygen in the air.
• The air we breathe in does not contain only oxygen, it is a mixture of many gases.
  Different organisms possess different respiratory organs.

Different types of respiration, respiratory organs with suitable examples

Respiratory organ	Type of Respiration	Animals
Lungs	Pulmonary	Mammals Birds, Reptiles and Amphibian
Gills	Branchial	Fishes, Crabs, Tadpole larva of frog
Skin	Cutaneous	Earthworm, Leech, Amphibians
Trachea	Tracheal	insects

• Respiration occurs in all organisms. In this process oxygen is taken and carbon dioxide and water vapour are released out.
• Stomata and lenticels help in exchange of gases in plants.

 

TS Board Telangana SCERT 7th Class Science Solutions 10th Lesson Nutrition in Plants Textbook Questions and Answers.

TS 7th Class Science 10th Lesson Questions and Answers Telangana – Nutrition in Plants

Question 1.
A potted plant is kept in light for a day and one of its leaves is tested for starch. The same plant is kept in the dark for two days and another leaf is tested for starch. Will there be any difference in the results of the two experiments? Give reasons for your answer.
Answer:

• When the plant is kept in light for a day, the leaves synthesize sufficient food by the process of photosynthesis.
• Light exposed Leaf ensures the presence of starch (food) in it. We can conclude the presence of starch with iodine test.
• Iodine test on leaf reveals us the photosynthetic rate and the formation of food (starch) by giving blue colour which appears in leaf.
• In contrary, when the same plant is kept in dark place for two days, the occurrence of photosynthesis is completely stopped because there is no exposure of light on leaves.
• Since there is no light, there is no food (starch) formation. As a result, the leaf of dark placed plant doesn’t show blue colour on iodine test.
• We examined the leaves of same plant when it is kept in Light for one day, and in dark place for three days.
• But the final results are in two different ways. One is with light exposed leaves which gives blue colour on iodine test.
• Another one is with dark area leaf which doesn’t give blue colour on iodine test.

Question 2.
What happens if leaves of a green plant are coated with oil? (Hint : What will be the effect on stomata?)
Answer:

• When leaves of a green plant are coated with oil, the stomata present on the surface of leaf will be closed.
• If stomata are closed with any other substance, the exchange of gases will be stopped. the gaseous exchange (oxygen and carbondioxide) will not take place.
• If stomata stops receiving carbondioxide, the photosynthetic rate decreases. As a result, food (starch or carbohydrates) formation stops.
• If there is no sufficient photosynthesis, the leaves release less oxygen to the atmosphere.
• Finally, there will be a decrease of oxygen in the atmosphere. Thus in turn, it affects all the organisms. It will impact on all the organisms.

Question 3.
Do you think saprophytes help us in keeping the environment clean? (Hint: What do saprophytes feed on?)
Answer:

• Saprophytes help us in keeping the environment clean. Most of the bacteria, all fungi come under saprophytes.
• Saprophytes are a type of heterotrophs (Which depend on other organisms for food).
• Some of the bacteria and fungi depend on other dead organisms to obtain nutrients.
• They decompose and degrade the complex molecules present in the dead organisms to simple molecules.
• Bacteria and fungi absorb these molecules through their body surface. Hence they are considered as saprophytes.

Question 4.
Differentiate between the following with some examples.
i. Parasite and Saprophyte
ii. Host and Parasite (Conceptual Understanding)
Answer:
i. Parasite and Saprophyte

Parasite	Saprophyte
1. Organism which lives inside or outside of another organism (host) is called parasite	1. Organisms which live on dead organisms are called saprophytes.
2. Only parasite is benefited	2) Saprophytes add several valuable nutrients to the medium in which they live
3. Body functions of the host are affected badly by the parasite	3. Saprophytes degrade and decompost the dead organism

ii. Host and Parasite

Host	Parasite
1. This is the organism which parasite invades.	1. This is the organism which invades host.
2. Host becomes a site of food for parasite	2. Parasite obtains the nutrients from the host.
3. Host becomes diseased and even die	3. Parasite affects the body of host badly.

Question 5.
Fill in the blanks and give reasons:

i. Lenticels are present on in pLants. (the bark)
Reason: Lenticels are present on the bark of plant through which exchange of air takes place.

ii. The food synthesized by the plants is stored as ‘starch)
Reason: In the plants. glucose is converted into starch for further use.

iii. Saprophytes depend on for food. (dead and decaying organisms)
Reason: They absorb complex molecules and convert into simple molecules.

Question 6.
Name the following.

i. Pores through which leaves exchange gases?
Answer: Stomata.

ii. Plants that act as scavengers of nature.
Answer: Fungi.

iii. Plants that share food and shelter.
Answer: Symbiosis.

iv. Plants that cannot make their own food and obtain it from host.
Answer: Parasitic plants.

Question 7.
Choose the correct answer:

i. Cuscuta is an example of (  )
A) Autotroph
B) Parasite
C) Saprophyte
D) Symbiosis
Answer:
B) Parasite

ii. Haustoria are (  )
A) roots
B) stems
C) leaves
D) All of them
Answer:
A) roots

iii. Raw materials involved in the process of photosynthesis ( )
A) Carbon dioxide
B) Water
C) Sun light
D) All of them
Answer:
D) All of them

Question 8.
Circle the insectivorous plant among the options given below. (Communication through Drawing and Model Making)
(a) Hibiscus
(b) Teak
(c) Nepanthus
(d) Aloevera
Answer:
(c) Nepanthus

Question 9.
Collect information about experiments of Joseph Priestly and Ingenhouz from internet and make a brief note on them.
Answer:
Joseph Priestly:

• Joseph Priestly was a famous biologist who conducted several experiments.
• He carried out a sequence of experiments on exchange of gases between plants and animals.
• He demonstrated that what animals were doing to the air was being reversed by plants.
• He concluded that the animals are making the air impure by releasing carbondioxide. Opposite to the animals, plants are making the air pure by consuming carbondioxide and releasing oxygen in plenty.

Ingenhouz:

• Ingenhouz was the botanist. He tried to repeat Priestley’s experiments under different conditions and found that only the green parts of plants can absorb carhondioxide when they are exposed to the sunlight.
• They prepare food and release oxygen into the air.
• By knowing the experiments of Ingenhouz, we learnt so many evidences.
• We are strongly in belief that plants utilise water from soil, take carbondioxide in the presence of sunlight and they prepare food.

Question 10.
Do you agree with Von Helmont? If nutrients absorbed by plants from soil is equal to the mass of plant tree what will happen ? Think and write your hypothesis.
Answer:

• I do agree with Von Flelmont’s hypothesis because apart from water and soil, there is other intake for the growth of plant and that is carbondioxide.
• According to him, nutrients absorbed by plants from soil is equal to the mass of plant or tree.
• But in early stages, plant is in very less weight.
• As it is growing year by year, it adds weight. Based on the results of Helmont’s experiment, more weight of the plant is seen.
• It showed natural growth irrespective of the consumed weight of the nutrients from the soil.
• Therefore, plant’s growth and their adding weight is not related with mass of the nutrients consumed from the soil.
• The weight of the plant is influenced by some other element apart from soil and water.
• If nutrients absorbed by plants from soil is equal to the mass of plant, the soil will lose its weight. It will affect other plants and animals.

Question 11.
Why are some plants called insectivorous plants ? Give reasons.
Answer:

• A few plants manufacture their own food. But they obtain some nutrients from insects.
• Leaves of these plants are specially modified to trap insects.
• They meet their nitrogen requirements from insects to get free from nitrogen deficiency
• Hence these plants are insectivorous plants. Eg: Droseras, Utricularia, Venusflytrap.

Question 12.
Designery leaves – select any broad leaved potted plant. Cut a card board with a design of your choice and seal the selected leaf with the card board. Let the plant stand under the sun for a week. Then remove the card board. You will get designer leaves plant. ‘fly to make more leaves with designs.
Answer:

Aim : To make a designery leaves from a broad leaved potted plant.
Requirements : Broad leaved potted plant, card boards, blade or knife clips.

Procedure:

• A healthy broad leaved potted plant is taken from the garden.
• A few card boards are designed in star shape and ‘L’ shape with blade or knife.
• These designed card boards are considered as lids.
• These lids act as light screens. Attach the light screens to some leaves.
• The light screens hold the leaves by a lid. Now the lids and light screens have cut designs.
• The plant is kept under the sun for a week. By the end of one week, the card boards are removed.

Observation: It is observed that the cut. design (star or L shaped) on the lid of the light screen appeared on leaves.

Reason: The leaf with light screen receives sunlight on the leaf through the cut design in the lid.

Question 13.
Collect a leaf. Take peels from both sides of the leaf and observe stomata size, shape and number under microscope with the help of your class teacher and write your findings.
Answer:
Aim: To observe stomata size, shape and number appeared on the leaves.

Requirements: A healthy green leaf (piper beetle), coloured nail polish; brush, low power microscope.

Procedure:

• A healthy green leaf (piper beetle) is taken.
• On both the surfaces, coloured nail polish is applied with a brush.
• Now the polish is allowed to dry.
• After complete drying, a peel of polish is taken out (gently) from the margin of the leaf.
• Similarly, peels are taken out from apex and basal side of both surfaces of the leaf.
• Each peel is mounted on a glass slide and observed under microscope.

Observation:

• It is observed that the pattern, frequency and type of distribution of stomata are rather enormous on the lower surface compared to upper surface.
• The size, shape and number of stomata are more on the lower surface.

Question 14.
Prathima said ‘Mushroom is also a p1ant. Is she correct ? How would you support her?
Answer:

• Mushroom is considered as plant organism. They are commonly called fungi.
• They do not contain chlorophyll.
• They are umbrella like structures which grow from the ground.
• They simply absorb organic material usually from the soil.
• These fungi do not depend on other living organisms.
• Since, they are independent of getting food material, they behave like plants.
• Hence, mushroom is a plant.

Question 15.
Photosynthesis is the way plants make food in every leaf by using different items. Write your feelings on this.
Answer:

• Photosynthesis is the basic important life process which is significant on this planet.
• Plants manufacture the food (starch) by utilising raw materials like carbon- dioxide and water by the process of photosynthesis.
• Photosynthesis enables the plants to release oxygen into atmosphere. That oxygen is essential for mankind.
• Photosynthesis helps to purify the atmosphere by absorbing carbondioxide and gives oxygen.
• This life process influences the expansion of the plant population further. It establishes a greater healthy environment.
• Photosynthesis is the only process that utilizes solar energy for synthesizing food.
• Man doesn’t have the capacity of synthesizing food like plants.
• The photosynthesis is a vital living mechanism.
• Leaf supports preparation of lood by receiving sunlight and carbondioxide.

TS 7th Class Science 10th Lesson Notes Nutrition in Plants

• Nutrition : Procurement of nutrients.
• Autotrophs : The organisms which synthesize food on their own.
• Chlorophyll : The leaves contain the green substance, chlorophyll.
• Photosynthesis : Green parts of plants use carbondioxide in the presence of sunlight along with water to make glucose / starch and other food material. This process of making food material is called photosynthesis.
• Stomata : Openings present on surface of leaves.
• Saprophyte : Saprophytes live on decaying organic matter.
• Insectivorous plants : Insectivorous plants fulfill their nitrogen deficiency by trapping insects.
• Carnivorous : The organisms that feed on herbivores.
• Symbiosis : In symbiosis, organisms share their food and shelter.

• Fungi : Lower developed plant organisms.
• In the year 1648, a Belgian scientist Jan Baptista Von Helmont conducted an experiment to show the variation between the weight of the soil and the plant that is grown in the same soil.
• The substances needed for the growth of a plant do not come from the soil only.
• Stephan Hales described the leaves as organs of transpiration.
• The process of loss of excess water from plant body is called transpiration.
• Priest ley carried out a sequence of experiments to demonstrate that what animals were doing to the air was being reversed by plants.
• Ingenhouz tried to repeat priestley’s experiments under different conditions and demonstrated that only green plants receive carbondioxide.
• Carbondioxide + Water Glucose + Oxygen
• Farmers sprinkle urea in rice or wheat fields whenever the leaves turn yellow. The leaves soon become green again.
• Plants that do not photosynthesize, depend on other means for getting their nutrition.

TS Board Telangana SCERT Class 7 Science Solutions 7th Lesson Electricity: Current and it’s Effect Textbook Questions and Answers.

TS 7th Class Science 7th Lesson Questions and Answers Telangana – Electricity: Current and it’s Effect

Fill in the missing words in the blank spaces in the following statements:

1. Wind is the air.
2. Winds are generated due to on the earth.
3. Near the earth’s surface air rises up where as air comes down.
4. Air moves from a region of pressure to a region of pressure.
Answer:
1. moving
2. expansion of air
3. hot, cool
4. high, low

Question 5.
Suggest two methods to find out wind direction at a given place.
Answer:

• Flying kites in the air enables us to know the direction of the wind. Naturally, the kite flies only along the direction of the wind to which it blows.
• Whirling of paper fan against the direction of blowing of wind. The above two methods help us to find out wind direction at a given place.

Question 6.
State two experiences that make you think that air exerts pressure. (Other than those given in the text).
Answer:
A. We can understand that air exerts pressure by doing the following two experiments.

• Hot water is poured in the plastic bottle. It is noticed that the temperature of the hot water is between 500C-60°C.
• The mouth of the bottle is closed with lid.
• Then the bottle is shaken to all sides.
• Lid is opened and the water is thrown away from the bottle. Again the bottle is recapped.
• Finally, it is observed that the sides of the bottle are pulled inwards. This proves that air has sideward pressure.

B. I collected a glass beaker, a glass tumbler, a coloured plastic ball and water.
Procedure:

• The glass beaker is filled with water more than half its capacity.
• The collected ball is immersed in the water beaker.
• It is observed that the ball floats on the water.
• A glass tumbler is inverted on the ball.
• We observed the ball goes down to the bottom along with glass tumbler.
• The rim of the glass tumbler remains on the surface itself. This shows that the air in the glass thrusts the water downwards.

Question 7.
While constructing a house, where do we construct ventilators, why?
Answer:

• Naturally we construct the ventilators above the windows, near the roof of house.
• The ventilators facilitate exhaustion of our exhaled air.
• When we breath out air, it goes up and expels out of the house through the ventilators.
• The air we breath out from the lungs is hot in its nature. Infact hot air possess less density.
• When density of air decreases it becomes less in weight.
• As a result the expired air goes up and is expelled out of the house through ventilators.

Question 8.
Explain why holes are made in banners and hoardings hanging in the open.
Answer:

• Holes are made in banners and hoardings which hang in the open air of the streets or grounds.
• When wind blows. it exerts pressure and force on the banner.
• The exerting pressure and force of the wind sometimes may damage the tied rope and cut the banner.
• If holes are made in the banner, the air passes through them easily.
• The holes reduce the force and pressure of the air and retain the banner to hang freely.

Question 9.
How will you help your neighbours in case cyclone approaches your village / town?
Answer:
I can help my neighbours during cyclones by the following way,

• I advice them not to come out of the houses during thunder storms.
• If houses are collapsed, I try to send the victims to the rehabilitation centres.
• T participate in the distribution of food, water and other necessities needed to the victims along with the public servants.
• Even if any one is injured. I take him/her to the nearest health centre or will call the doctor to the specific area.
• I participate in the removing of collapsed trees and any debris.
• I can console the victims to relieve them from mental stress and agony.

Question 10.
In the day time, when we go to the sea, the air blows towards us and does not go towards the sea. Explain.
Answer:

• In the day time, when we go to the sea, the air blows towards us and does not go towards the sea.
• Because, the land heats up faster than the sea. So warm air raises over the land during the day.
• The hot air goes up and the pressure decreases on land.
• As a result the cool air from the surface of sea blows into the land.
• The cool air exerts more pressure.
• The air from high pressure areas to low pressure area keeps the wind blowing from sea surface o land during day time.

Question 11.
Which of the statements given below is correct?
a. In winter, the winds flow from the land to the ocean.
b. In summer, the winds flow from the land towards the ocean.
c. A cyclone is formed by a very high pressure system with very high speed winds revolving around it.
d. The coastline of India is not vulnerable to cyclones.
Answer:
The statements ‘a’ and ‘c’ are true. The statements ‘b’ and ‘d’ are not correct.

Reason for statement ‘a’:
During winter, the high pressurised cool air goes on to the surface of sea and low pressurised air with less density blows into the land.

Reason for statement ‘b’:
During summer, warmth air with less density and pressure goes up and down pressurised air blows from sea surface to the land.

Reason for statement ‘c’:
When the wind gets tremendous pressure, its speed of blowing also rises. Very high pressurised wind when it blows with high speed, it revolves around it.

Reason for statement ‘d’:
Our country’s coast line is highly vulnerable to the cyclones. Cyclones may hit any coastal region of India due to formation of severe low depressions.

Project Work

Read the following procedure and make your own anemometer.

Question 12.
Collect the following items and prepare the anemometer on your own.
a. 4 small paper cups
b. Two strips of the card board 20 cm long; 2 cm width.
c. Gum
d. Stapler
e. Sketch pen
f. Sharpened pencil.
Answer:
Aim : To make the anemometer with the collected items.

Procedure :

• Two strips of the cardboard are taken. Crosses are drawn on the strips as shown in the figure.
• The strips are fixed at the centre, putting one over the other, they make a ‘+‘ sign.
• Four small paper cups are fixed at the end of the strips. One of the fixed cups is coloured with sketch pen.
• It is seen that all four cups should face in the same direction.
• A pin is pushed through the centre of the strips and strips are attached to the sharpened pencil.
• The strips are checked that they rotate freely when we blow on the cups.
• The entire equipment is called anemometer

Working of anemometer : Number of rotations for a minute will give an estimated speed of the wind.

Question 13.
Collect some articles and photographs from news papers and magazines about storms and cyclones. Make a story on the basis of what you learnt in this chapter.
Answer:
The above collected pictures of satellite images reveal how cyclones and depressions occur in the seas and oceans.

Formation of cycle:

• Our country is in tropical region.
• Tropical cyclones are like giant engines that use warm moist air as fuel.
• The warm air rises causing an area of lower air pressure below.
• Air from surrounding areas of high air pressure pushes into the low pressure areas. Then the ‘new’ air becomes warm and rises too.
• As the warm air continues to rise, the surrounding air swirls – in to take its place, the water from the sea surface also comes up with the air as we have seen in the pictures.
• As the warmed moist air rises and cools off, the water in the air forms clouds.
• The whole system of clouds and winds spins and grows, fed by the ocean’s heat and water evaporating from the surface.
• Satellite images help us to predict the path of the cyclones to some extent.

Question 14.
Interview eye witnesses to collect the actual experiences of people affected by a cyclone.
Answer:

• How did you feel when cyclone hit your area?
• What was the speed of winds during cyclone?
• Where did you stay during heavy cyclone?
• Is there any damage occured to your home?
• How have you saved you and your family from cyclone ?
• Did you seek any one’s help at that time?

Question 15.
More fun with air.
Do the following activities and write your findings.

A. Take an empty bottle and place it on the table as shown in figure. Place a cotton ball just inside its mouth. Now try to blow air on the ball to send it into the bottle, and then try the activity with bottles of different sizes. Throw a challenge to your friends whether they can send the cotton ball inside the bottle by blowing air. Are you surprised ? Why did this happen ? Think about it and discuss with your friends.

Answer:
The blowing air could not send the cotton ball inside the bottle because the air present in the bottle exists pressure towards outside of the bottle. The same results are seen in the activities done with bottles of different sizes.

B. Can you blow out the ball from funnel?
Take a funnel and ball, keep the funnel in your mouth as shown in figure. Keep the ball in the funnel. Blow air through the funnel and try to send out the ball from funnel. What happens ? Have you succeeded in sending the ball out?

And then place the ball on your hand and put the funnel over the ball as shown in figure. Now blow air forcefully through funnel and try to blow out the ball from the funnel (while blowing air, remove hand.)

• What did you observe?
• What did you expect?
• What happens?

Try to answer and discuss with your friends.
Answer:

• When we blow air through the funnel, the ball jumps but does not fall from it.
• It is because blowing air is some what less denser and the air above the funnel exerts downward pressure.
• That influences the ball to jump over funnel.
• Hence we may not succeed in sending the ball out of the funnel.
• The second picture also tells us that the ball has not fallen because the size of the ball and radius of the funnel tube is same. We expect that the ball would fall from the funnel.
• Moreover, the air below the funnel exerts upward pressure.

C) Flow of air.
Take a large plastic bottle and a two holed rubber cork that fits firmly into its mouth. Also take two glass tubes. Tie a coloured balloon to the lower end of one of the glass tubes. Insert the glass tubes into the two holes of the cork. The glass tubes should fit tightly in the holes. Close the mouth of the bottle with the cork and seal it with sealing wax to make the bottle airtight. The balloon should be inside the bottle as shown in fig.
Now suck air out of the bottle through the tube that doesn’t have a balloon attached to it.

• What happens to the balloon?
• Why do you think this happened?

Answer:

• When we suck air out of the bottle through the tube, the balloon starts bulging itself.
• When the air is sucked out of the bottle, the pressure inside the bottle decreases.
• At that time, air from outside exerts downward pressure on the glass tube which is fixed with balloon.
• Downward pressure of the air enters the tube and fills the balloon to some extent.
• Then the balloon swells with high pressure which is more than that of air free bottle.

TS 7th Class Science 8th Lesson Notes Air, Winds and Cyclones

• Wind : The air around us is rarely still. It moves continuosly from one direction to another. The movement is in many directions. We call it wind.
• Expansion : Air expands on heating and contracts on cooling.
• Anemometer : The instrument used to measure the speed of air.
• Cyclone : An extremely large, powerful and destructive storm with very high winds that turn around an area of low
  pressure.
• low pressure : Decrease in pressure of air in a specific area causes low pressure.
• High pressure : The pressure increases in a specific area.
• Air around us exerts pressure.
• Warm air rises up whereas compara ti ve! y cooler air tends to sink towards the earth surface.
• As warm air rises up, pressure at the place is reduced and the cooler air noves into that place.
• Uneven heating on the earth causes wind movements.
• It has become easier to study cyclones with the help of advanced technology like satellites and radars.

TS Board Telangana SCERT Class 7 Science Solutions 7th Lesson Electricity: Current and it’s Effect Textbook Questions and Answers.

TS 7th Class Science 7th Lesson Questions and Answers Telangana – Electricity: Current and it’s Effect

Question 1.
Draw the symbols of the following electric components.
a. Cell
b. Battery
c. Switch
d. Electric bulb
Answer:

Question 2.
Draw an electric circuit diagram consisting of a cell, a bulb and an electric switch.
Answer:

Question 3.
In a series connection of bulbs, if one bulb fails, why do all other bulbs go OFF?
Answer:
In a series connection, if one bulb fails, the circuit breaks. So current stops to flow in the circuit. Then the other bulbs also go OFF.

Question 4.
Write the differences between series connection and parallel connection.
Answer:

Series connection	Parallel connection
1. In a series circuit, electricity has a single path to flow through.	1. In a parallel circuit, there is more than one path for the electricity to flow.
2. All the electrical components are connected in this single path.	2. The electrical bulbs are connected in different paths of the circuit.
3. If any one of the electrical components fails to function, the circuit breaks. No electricity flows through the circuit.	3. Even if a bulb fails to glow, the circuit does not break completely. Electricity flows through the other paths. So other bulbs glow.
4. If the number of cells increase in series, the bulbs glow brighter and brighter.	4. The brightness of the bulbs does not increase much with increase in the number of cells connected parallel.
5. Cells are generally connected in series, to increase the voltage in the circuit.	5. All electrical components in our houses are connected in parallel.

Question 5.
What is the advantage of Miniature Circuit Breaker?
Answer:
Now a days, Miniature Circuit Breaker (MCB) is increasingly being used in place of fuses. These are switches which automatically turn off when current in a circuit exceeds safe limit.

Question 6.
Fill in the blanks:
a. Longer line in the symbol for a cell represents its …………….. terminal. (positive)
b. Smaller line in the symbol for a cell represents its …………….. terminal. (negative)
c. The combination of two or more cells is called a …………….. (battery)
d. Safety device used in electric circuit is …………….. (fuse)
e. The device used to close or open an electric circuit is …………….. (switch)
Answer:
a. positive
b. negative
c. battery
d. fuse
e. switch

Question 7.
Mark ‘T’, if the statement is true and ‘P, if it is false. Give reasons for your choice of answer.

a. In series circuit, the electricity has only one path.
Answer: True.
Reason : There is only one path for the elctricity in a series circuit. So if any one of the electrical components fails to function, the circuit breaks. No electricity flows in the circuit. The bulb does not glow.

b. In parallel circuit the electricity has more than one path.
Answer: True.
Reason : Each bulb in a parallel circuit is connected in a separate path through which electricity can flow. So even if a bulb fails to glow, other bulbs continue to glow, since the circuit is not broken.

c. To make a battery of two cells, the negative terminal of one cell is connected to the negative terminal of the other cell.
Answer: False
Reason : In a battery, cells are connected in series. Then only more electricity flows through the circuit.

d. When the electric current through the fuse exceeds a certain limit, the fuse wire melts and breaks.
Answer:True
Reason: A ‘fuse wire’ with required specifications is used in the circuit, depending upon the ‘load’. When the current through the ‘fuse’ exceeds this limit, the fuse wire melts. Then the circuit breaks and no current flows in the circuit. When the switch is in the OFF position, the circuit is open. No current flows is it.

e. The switch is used to close or open an electric circuit.
Answer: True

Reason : The switch can be placed any where in the circuit. If the switch is in the QN position, the circuit is complete from the positive terminal of the battery (+) to the negative terminal (-). Then current flows through this closed circuit.
When the witch is in the OFF position, the circuit is open. No current flows in

Question 8.
Choose the correct answer.

i. Arun buys four bulbs of 15 W. 40 W. 60 W and 100 W. Which one should be used in his room as right bulb ‘ (a)
a) 15W
b) 40 W
c) 60 W
d) 100 W
Answer:

ii. Device used w cos or open an electric circuit is (c)
a) electric bulb
b) battery
c) switch
d) fuse
Answer:
c) switch

iii. Which one of the following is used as a source of light? (d)
a) Cassette player
b) Electric mixer
c) Rice cooker
d) Table lamp
Answer:
d) Table lamp

iv. Safety device used in electric circuit is (d)
a) electric bulb
b) battery
c) switch
d) fuse
Answer:
d) fuse

Question 9.
Visit your classmates houses. Find out the meter readings of three months. Record your observations. Ask your parents about how electricity bill is paid?
Answer:
Electricity bill is paid at either Mee-seva or electricity department offices.
Bill should be paid within a month after taking out through electronic billing machine.

Question 10.
Draw the symbols for the electrical components in the table.
Answer:

Question 11.
Draw the circuit diagram for the following series connection.
Answer:

Question 12.
Match the following.
1. Cell ( ) a) Used to open or close a circuit
2. Switch ( ) b) Safety device used in electric circuit
3. Circuit ( ) c) A complete path for the flow of an electric current
4. Miniature circuit breaker ( ) d) Reset by hand, circuit becomes complete once again.
5. Fuse ( ) e) A device which converts chemical energy into electrical energy.
Answer:
1 – e
2 – a
3 – c
4 – d
5 – b

TS 7th Class Science 7th Lesson Notes Electricity: Current and it’s Effect

• Cell : Electric cell is a source of electric energy.
• Battery : Two or more cells joined together to form a battery.
• Fuse : An ‘electric fuse’ is a small piece of wire made of a low melting alloy. It is used as a safe device in electric circuit.
• Series circuit : When the negative terminal of the first cell is connected to the positive terminal of a second cell and so on, then the cells are said to be connected in series.
• 
• Parallel circuit : When the positive terminals of the cells are connected to one common point and the negative terminals are connected to another common point, then the cells are said to be connected in parallel

  

• Bulbs in series : When bulbs are connected in series, if one of the bulbs does not glow, then the other bulbs also do not glow. This is due to break in the circuit.
• Bulbs in parallel : In an electric circuit, bulbs are said to be connected in parallel, if the first terminals of all the bulbs are connected to a common point and similarly all the second terminals, to another common point.
  
• Tube light : Wastage of electricity can be reduced by using fluorescent tube lights in place of bulbs.
• Compact Fluoroscent Lamps : CFLs reduce wastage of electricity.
• Miniature Circuit Breaker : Now – a – days. in place of ‘fuses, MCB (Miniature Circuit Breaker) is widely used.
• Watt : A measure of electricity.
• Circuit diagram : This indicates connection of battery, bulb and switch.
• Heating effect of current : Nichrome coils of electric appliances get heated up on passing of electricity.
  Eg: Electric heater
• Switch : Switch is a simple electrical device, used to break the electrical circuit or to complete it.
• Electric cell is a source of electric energy.
• Electric cell produces electricity from the chemicals stored inside it.
• Dry cell converts chemical energy into electrical energy.
• An electric cell stops producing electricity, when the chemicals in the electric cell are used up.
• A dry cell is a modified form ofLeclanche cell.
• In the dry cell, zinc vessel is negative electrode and carbon rod is positive electrode.
• The dry cells are easy to handle, as they do not contain any solutions. So they are widely used in Radios, Torch lights, Tape recorders etc.
• The cells in the torch light are kept in series.
• An electric bulb has a filament made of tungsten metal. It is connected to the terminals of the bulb.
• An electric bulb glows, when electricity passes through the filament of the bulb.
• A fused bulb does not glow, as no current passes through its filament.
• If an electric circuit provides a complete path for current topsoil between the two terminals of the electric cell, then it is called a ‘closed circuit’.
• In an electric circuit, the direction of current is taken to be from the positive to the negative terminal of the electric cell.
• When bulbs are connected in parallel, even if one bulb does not glow, the other bulbs continue to glow. This is because, only this part of circuit breaks and all other circuits remain intact.
• The filament of an electric bulb converts electrical energy into heat and light.
• The electrical appliances like electric iron, electric cooker and electric heater contain a coil of wire made of Nichrome. This is called ”heating element” (or filament) of the appliance. (Nichrome = Nickel + Chromium)
• Most of the elctricity that we use at home and at school is ‘alternating current’ (A.C.). A bulb with a high wattage (Ex : 100 W) consumes more electricity and gives a brighter light.
• The wattage of a bulb measures, how “powerful” the bulb is.
• A KWH (kilowatt-hour) is also called, ‘one unit’ of electricity.
• 1 Kilowatt = 1000 Watts (1 KW= 1000 W)
• If one kilowatt of electric energy is used for 1 hour, the consumption of electricity is ‘1 unit’.

 

TS Board Telangana SCERT Class 7 Science Solutions 6th Lesson Weather and Climate Textbook Questions and Answers.

TS 7th Class Science 6th Lesson Questions and Answers Telangana – Weather and Climate

Question 1.
What aspects should you observe to know and predict the weather of your village?
Answer:
Temperature, rainfall, wind speed, wind direction, humidity, etc., sun rise and sunset times.

Question 2.
Read a newspaper, collect the weather report in it. Write about the various elements of the weather mentioned in the report.
Answer:

Various elements of the weather mentioned in the report of News paper.

• Max : Maximum temperature.
• Min : Minimum temperature.
• RH : Relative humidity.
• Rainfall
• Sun set time
• Sun rise time
• Moon set time
• Moon rise time.

Question 3.
Where is the meteorological department in your area ? How is it useful to you?
Answer:
In our area the nearest meteorological station is situated at Machilipatnam. It undertakes observations,communications, forecasting and weather services which are very useful to farmers, people who are living near coastal regions.

Question 4.
It is hot and sweaty at a place. What could be the possible reasons for that?
Answer:
Reasons for hot and sweaty conditions:

• High temperature.
• Presence of more humidity in the atmosphere.
• Occurrance of atmospheric pressure.

Question 5.
Write true or false. Give reasons.
Answer:
a. Minimum temperature is recorded in early morning. ( True )
b. The direction and speed of wind is found by an Anemometer. ( True )
c. In summer the winds blow towards the earth from the seas/ocean in the afternoon. ( True )
d. In our state the maximum temperature is recorded in the month of July. (False)

Question 6.
Observe the graph showing rainfall (in mm) of a place from August to December. Write down the observations from it and what inference you can draw.
Answer:

Observations from the above graph:

• This graph represents rainfall (in mm) of a place from August to December.
• Rainfall is highest in the month of November, i.e., 78 mm.
• Rainfall is lowest in the month of September i.e.10 mm.
• Rainfall increased from September to November.
• In a month of August, the rain fall is 18 mm.

Question 7.
Why do people need and observe weather ?
Answer:

• Farmers to plan their agricultural activities.
• People near coastal areas to escape from tsunami or cyclone.
• People to take care and protect themselves from summer, rain and winter.

Question 8.
Explain these symbols used in a weather forecast report.

Answer:

Question 9.
Collect the weather reports from the news papers and make a profile of the weather in a city?
Answer:
Weather report (28-05-2018)
Telangana State

Hanamkonda	41	23	0	0
Hyderabad	39	25	tr	9
Mahabubnagar	39	27	0	26
Nizamabad	41	26	0	tr
Ramagundam	41	26	0	1

The columns show maximum and minimum temperature in Celsius, rainfall during last 24 hours (trace) and total rainfall in mm since May, 28, 2018.
The maximum temperature in Hanamkonda = 41° C
Minimum temperature = 23° C
Rainfall during last 24 hours = 0
Total rainfall in mm since 28.5.2018 = 0 mm.

Question 10.
Every year we have floods in the rainy season. Why ?
Answer:

• Due to heavy rainfall
• Deforestation
• Poor dams
• When soil and vegetation does not absorb rain water.
• Urbanisation : Occupation of rivers, canals, lakes.
• Poor drainage system.

Question 11.
Observe your surroundings and try to predict how tomorrow would be ?
Answer:
Today is hot and dry. So tomorrow would also be hot and dry.

Question 12.
Priya’s mother said “It is very hard to stay at Vizag during summer”. Why did she say so ?
Answer:
In places near a river or in coastal regions, the weather in summer is sweaty, due to more humidity. Vizag is in coastal region. So Priya’s mother said so.

Question 13.
Collect different news papers and compare the weather reports. Are they same or not ? Why ?
Answer:
The weather reports in different news papers are same, because all these reports based on satellite photos and reports given by meteorological stations.

Question 14.
Observe your surroundings immediately after rain. Explain your feelings in the form of a song.
Answer:

• Rain – Rain
• Brings life divine
• Kisses the earth mother
• Changes the hot weather
• Birds welcome rain – chirping
• Plants embrace rain – nodding
• Children invite rain – dancing

Question 15.
Prepare some questions to conduct a quiz programme in your class on this chapter ?
Answer:

• Name the instrument used to find humidity.
• The scientist who invented maximum minimum thermometer ?
• Name the department which studies climate of our country ?
• Name the instrument used to measure wind direction.
• Rainfall a particular place is measured in which units.
• What is the instrument used to measure rainfall ?
• The quantity of water vapour in air is called
• The nearest Meteorological station is situated at
• Predict a city, where the humidity is more .
• What are the liquids present in maximum, minimum thermometer ?

In Text Questions And Answers

Let us do – 1

Observe the following table. This is about weather of Amaravathi for the next three added consecutive days. Amaravathi is the capital of Andhra Pradesh.

Question 1.
What aspects do you see in this weather record?
Answer:
The aspects in the weather record are.

• Maximum temperature
• Minimum temperature
• Rainfall
• Sky may be
• Wind
• Humidity
• Sunrise
• Sunset

Question 2.
On which day did it rain?
Answer:
Day-2

Let us do – 2. Plotting graph

Question 1.
Take a newspaper or watch the TV news and record the maximum and minimum temperature, rainfall, humidity and wind pattern of any 3 cities or towns in a table. Do this over a week. (Expt/Obs)
Answer:

P = Peddapalli
W = Warangal
K = Kareemnagar
C = Cloudy
LS = Little shower
R = Rainy
H = Hot
VMB = Very mild breezes
MB = Mild breeze
GB = Good breeze

Question 2.
Take the figures of the maximum temperature over a week and plot the data on a graph. For example one is given here.
Answer:
Ploting a graph by taking maximum temperature over a week in Hyderabad.

Let us do – 3. Understanding weather reports

Report 1 :
Isolated rain or thunder showers are lightly to occur over Mahabubnagar, Nagarkurnool, Khammam and some parts of Ranga Reddy districts. Mainly dry weather will prevail over southern Telangana districts. Sky should be cloudy for the next two days in Warangal district.

Report 2 :
According to meteorological department report 42°C maximum temperature recorded at Ramagundam of Karimnagar district and 29°C minimum temperature recorded at Madhira of Khammam district. Because of cumulonimbus clouds 2 mm of rainfall was recorded in Hyderabad. Scattered rainfall recorded in some parts of interior Telangana. Remaining part of Telangana state was dry.

Question 1.
Which report explains what will happen?
Answer:
Report – 1 explains what will happen.

Question 2.
What aspects of the weather are discussed in both the reports?
Answer:
The aspects discussed in both the reports are

• Maximum and minimum temperatures.
• Rainfall and weather conditions in different regions of Telangana.

Question 3.
What are the differences in the weather situation given by the two reports?
Answer:
Report -1, explains the future conditions. So it is a weather forecast.
Report – 2, explains about past conditions. So it is a weather report.

Let us do – 4.

Take a maximum minimum thermometer (MMT) from your school laboratory. Let us find out how to use it to measure the two temperatures.
Answer:
1. Maximum minimum thermometer consists of 2 bulbs.

• Cylindrical bulb ‘A’,
• Spherical bulb ‘B’ contains alcohol.

2. When temperature increases, the alcohol in the bulb ‘A’ expands and mercury in the U-tube goes up to the bulb ‘B’ side and indicator I₁, also moves up. This indicates maximum temperature of the day.

3. If the temperature decreases, alcohol in the bulb ‘A’ contracts then the mercury in the U-tube goes to the ‘A’ bulb side and the indicator I₂ also moves up. This indicates minimum temperature of the day.

4. After taking readings the indicators I₁ and I₂ are brought to their original places by using a magnet.

Day	Date	Maximum temperature
1	10-12-2016	31°C
2	11-12-2016	32°C
3	12-12-2016	32°C
4	13-12-2016	32°C
5	14-12-2016	32°C

 

Graph showing the variation of maximum temperature during 10 to 14 Dec. 2016 at Khammam.

1. For how many days did Pravin observe the temperature of his village?
Answer:
Pravin observed the temperature of his village for 5 days.

2. On which day was the highest temperature recorded?
Answer:
Continuously from 11-12-2016 to 14-12-2016, 4 days recorded. Highest temperature recorded.

3. On which days did the lowest temperature fall?
Answer:
On 10-12-2016 the lowest temperature was recorded.

4. Do you find any relation between 10th and 14th of December 2016? What is that?
Answer:
From 10-12-2016 to 14-12-16 temperature increased by 1°C

5. Make a graph with your observations of maximum and minimum temperatures.
Answer:

Letus do-6

Collect weather reports of a nearby city from newspapers. Tabulate your observations for a week and compare them. Write your observations in your notebook about the temperature that you have measured.

1. When was the maximum temperature recorded?
Answer:
Maximum temperature was recorded at 12 Noon.

2. When was the minimum temperature recorded? Why?
Answer:
Minimum temperature was recoorded at 7 AM. It is morning time.

3. Is there any similarity in temperatures between your school and the nearest city?
Answer:
They are nearly similar.

Let us do – 7.

Observe the direction of wind. Tabulate your observation of wind direction.

1. Does the wind move in the same direction the whole day?
Answer:
The direction of wind changes from time to time.

2. In which direction does it move in the morning?
Answer:
In the morning time the wind moves in west direction.

Let us do – 8.

Take about 10 ml water in a test tube. Heat it on a Bunsen burner or I candle. What happens ? Think about it.

1. Why do bubbles appear in water?
Answer:
When water is heated, it changes into water vapour. The vapour enters into the air in the form of bubbles.

2. Why is the water level reducing?
Answer:
Some water is evaporated in the form of vapour. So water level reduced.

3. Where did the water go?
Answer:
Water went into atmosphere in the form of water vapour.

Let us do – 9.

Observe the weather report (temperature and rainfall) of two places in our state. The average temperature and rainfall for the last 25 years of the particular month is given in the table.

1. In which month was maximum temperatures recorded ? Why?
Answer:
In the month of May, maximum temperatures recorded due to summer.

2. Comparatively which place is hot ? Why?
Answer:
Comparatively Ramagundam is hotter than Hanumakonda.

3. How can you say Hanumakonda is cooler than Ramagundam in summer?
Answer:
Average temperature of Hanurnakonda in May is 33°C, whereas in Ramagundam it is 41°C. So we can say Hanumakonda is cooler than Ramagundam in summer.

Let us do – 10.

1. Why do people living in hot and humid region wear cotton clothes ?
Answer:
Because if humidity is high, we feel sweaty so people living in that regions wear cotton clothes.

2. In which season is the quantity of moisture in the air high ?
Answer:
In summer the quantity of moisture in the air is high because of evaporation.

Let us do – 11.

Observe features of the following states, and specific places in India from an ATLAS. Try to write down something about the climate in these areas.

S.No.	State	Climatic Condition
1	Kerala	Rainy
2	Telangana State	Hot
3	Rajasthan	Very hot
4	Jammu & Kashmir	Cold
5	West Bengal	Humid

TS 7th Class Science 6th Lesson Notes Weather and Climate

• Weather : The temperature and other conditions such as sun, rain and wind. Weather affects our life.
• Forecast : The report that explains future conditions is called a weather forecast.
• Temperature : Temperature is a measure of how hot or cold a place or thing is. We can measure temperature of a place with maximum and minimum thermometer.
• Climate : If the same weather reoccurs periodically at a place it is considered as climate of that place.
• Humidity : The quantity of water vapour (moisture) in air is called humidity’.
• The factors hot, cold, winds, rain etc., describe the weather of a place.
• The weather of a place can change even day.
• Temperature, rainfall, wind – speed, humidity etc., are called components of weather.
• Farjners estimate the rainfall based on the wetness of the soil after the rain. They call it as “PADUNU”
• Meteorologists measure the rainfall using a ‘Rain gauge’. It is also called ‘Udometer’ or ‘Pulvinometer’ or ‘Ombrometer’.
• Rainfall of a particular place is expressed in millimeter (m.m.), centimeter (c.m.) with a rain gauge.
• ‘Anemometer’ is used to measure wind speed and direction.
• Climate of a place can be defined after 25 years of weather observations.
• We adjust to the climate to live comfortably.
• The Indian Meteorological Department (I.M.D) studies climate of our country.
• The report that explains about past conditions is called a weather report.
• Humidity is measured by hydrometer.

TS Board Telangana SCERT Class 7 Science Solutions 5th Lesson Heat-Measurement Textbook Questions and Answers.

TS 7th Class Science 5th Lesson Questions and Answers Telangana – Heat-Measurement

Question 1.
The body temperature of Srinath is 99°F. Is he suffering from fever? If so, why?
Answer:
Yes, Srinath is suffering from tèver, because his body temperature is beyond normal level (98.40 F). The rise in temperature may be due to other infections or by taking spoiled food and water.

Question 2.
Why do we use Mercury in the thermometer? Can water be used instead of Mercury ? What are the problems in using it?
Answer:
We use Mercury in the thermometer instead of water due to the following properties.

• Its expansion is uniform
• It is opaque and shining
• It does not stick to the sides of the glass tube
• It is a good conductor of heat.

If we use water instead of mercury, we can’t see the accurate reading of temperature, because water evaporates on high heating. It doesn’t show expansion clearly.

Question 3.
Temperature of Srinagar (J & K) is – 4°C and Paderu (AP) is 3°C. Which of them has greater temperature ? What is the difference between the temperatures of these too places? (Conceptual Understanding)
Answer:
The temperature of Paderu (AP) is 7°C greater than Srinagar.
The temperature in Kashmir ( – 4°C) goes beyond the freezing point.
The temperature in Paderu is very near to 0°C (freezing point).

Question 4.
During winter mornings why do people stand in the Sun ? Explain.
Answer:
In winter, we feel cold inside the house due to less temperature Hence. people stand in the sunlight to get some heat.

Question 5.
After walking some distance on a hot summer day, why do we prefer to go into the shade?
Answer:
After walking some distance on a hot summer day, we feel very tired. The temperature of the body is lesser compared to out side hot weather. In order to withstand such hot conditions, we feel to stay in the shade until we get relaxed. So, we prefer to go into the shade and get relaxed.

Question 6.
Srikanth takes a sip of cold drink and feels the chill. Guess what its temperature is? Try to measure it.
Answer:
The temperature of cold drink will be at about 5°C. If we measure this temperature by using thermometer, it will be more or less 5°C.

Question 7.
Jyothi was prepared to measure the temperature of hot water with a clinical thermometer. Is it right or wrong ? Why?
Answer:

• It is wrong, because in a clinical thermometer, we can measure the temperature only upto 45°C.
• But the temperature of hot water will be above 45°C.
• If we measure the temperature of hot water with a clinical thermometer, it will break.
• Clinical thermometer is designed to measure only our body temperature.

Question 8.
Swathi kept a laboratory thermometer in hot water for sometime and took it out to read the temperature. Rani said it was a wrong way of measuring
temperature. Do you agree with Rani? Explain your answer.
Answer:
Yes, I agree with Rani.

• Laboratory thermometer is suspended for sometime in the boiling vessel with the help of ring stand.
• Therefore, we will measure the temperature of boiling waler until it reaches boiling point (100°C)

Question 9.
Why do we jerk a clinical thermometer before we measure body temperature?
Answer:
The thermometer has a neck in the fluid column. So the fluid mercury column would not come down readily after being taken out from the patient’s mouth. Therefore, jerking the thermometer is to ensure it is properly reset.

Question 10.
Heat energy is converted into other forms of energy. Give some examples.
Answer:
Heat energy is converted into other forms of energy. Some of the examples are:

• Heat energy in the steam engine is converted to mechanical energy to move the vehicles.
• Solar energy is converted into electrical energy.

Question 11.
Prathima said ‘Heat is a form of energy’. How do you support her?
Answer:
Heat is a form of energy’ because different kinds of energies are being converted to heat and in the same way heat energy is converted into other forms of energy.
Ex :

• Running of steam engine by converting heat energy into mechanical enerqy.
• Production of electricity in thermal power stations by burning of coal.

Question 12.
Why is a clinical thermometer not used to measure the temperature of air?
Answer:
For the measurement of temperature, the bulb of clinical thermometer needs to be in close contact with that object. So we can not measure the temperature of air by using clincal thermometer.

Question 13.
Fill in the blanks.
a. Doctor uses ………………….. thermometer to measure the human body temperature.
b. At room temperature mercury is in …………………..  state.
c. Heat energy transfers from …………………..  to …………………..
d. -7°C temperature is …………………..  than 0°C temperature.
Answer:
a. clinical
b. liquid
c. hotter body, colder body
d. lesser

Question 14.
Match the following.
i) Clinical thermometer (E) A) A form of energy
ii) Normal temperature of human body (C) B) 100°C
iii) Heat (A) C) 37°C
iv) Boiling point of water (B) D) 0°C
v) Melting point of water (D) E) Kink
Answer:
(i) – E, (ii) – C, (iii) – A, (iv) – D

Question 15.
Use the Thermometer and record the temperature in your school daily at mid-day meals time in the following table. Record temperature for a month.

• On which day was the temperature highest ? What could be the reason?
• On which day was the temperature lowest ? What could be the reason?
• What was the average temperature during the month?

Answer:
On 13-03-2018, temperature was highest.
On 15-03-2018, temperature was lowest because of cloudy atmosphere.
Average temperature = 35.5°C

Question 16.
Draw the diagram of a clinical thermometer and label its parts, What is the use of kink in a clinical thermometer?
Answer:
Kuir prevents mercury level from falling on its own.

Question 17.
Draw the diagram of a laboratory thermometer and label its parts. How does it differ from a clinical thermometer?
Answer:

• Clinical thermometer has ‘kink’ but a laboratory thermometer does not have, which prevents mercury level from falling on its own.
• The range of temperatures is also different.
• In a laboratory thermometer, the range of temperature is marked from -10°C to 110°C.
• In clinical thermometer, the temperature is marked from 35°C and ends with 45°C.

Question 18.
Measure the body temperature between fingers, under the tongue, armpit, folded hands, folded legs etc. Is it the same ? Does the body temperature remain the same after jumping ten times ? Why?
(Or)
Tabulate the temperatures you measured at various parts of the body. Write a report
Answer:

Body Parts	Body Temperature (°F)
1. Between fingers 2. Under the tongue 3. Armpit 4. Folded hands 5. Folded legs	95°F 98.8°F 98.4°F 97.9°F 97.5°F

No, the temperature varies at different parts of body. After jumping ten times, the body temperature increases by 0.2°F because while jumping, muscular energy is converted into heat energy.

Question 19.
Collect information from hospital/health centre about the precautions to be taken while reading temperature with a clinical thermometer.
(Or)
What precautions you came to know from hospital while reading temperature with a clinical thermometer? (Information Skills and Projects)
Answer:
Precautions to be taken while reading temperature with a clinical thermometer:

• Hold it firmly by the end and give it a few jerks. It is to bring the mercury column to the normal level.
• While reading the temperature, place the thermometer under patient’s tongue or armpit. After one minute, take it out and note the reading.
• Wash the thermometer with an antiseptic solution for every use.

Question 20.
Measure the temperature of water in normal conditions. If you add the following substance to the water, do you find any difference in temperature? Predict and verify.

Water temperature in Celsius	Water (100ml each time) mixed with two table spoonful of each	Prediction	Temperature of the solution immediately after mixing the substance
	Glucose	Decrease
	Washing powder
	Baking soda
	Sugar
	Common salt

Answer:

Water temperature in Celsius	Water (100ml each time) mixed with Two tablespoonful of each	Prediction	Temperature of the solution immediately after mixing the substance
30°C	Glucose	Decrease	25°C
30°C	Washing powder	Increase	36°C
30°C	Baking soda	Increase	34°C
30°C	Sugar	Does not change	30°C
30°C	Common salt	Does not change	30°C

Yes, by adding some substances, the temperature of water increases and for some substances, it decreases because of changes in the chemical reaction.

Let Us Do

1. Let us do this :

Some of the objects are given in the table. Mark these objects as hot or cold?

Object	Cold	Hot
Ice Cream
Fruit Juice
Metal Chair kept in the sun
Spoon in cup of hot tea

Answer:

Object	Cold	Hot
Ice Cream	✓
Fruit Juice	✓
Metal Chair kept in the sun		✓
Spoon in cup of hot tea		✓

 

2. Let us do this:

Conservation of energy.

Question 1.
Did you ever bathe with cold water during winter? What happens?
Answer:
We will feel very cold. We feel chill in severe winter.

Question 2.
What do you do to protect yourself from cold?
Answer:
We protect ourselves from cold by wearing woollen clothes.

Question 3.
How do you get hot water in winter?
Answer:
By heating water.

Question 4.
Generally we heat water to get hot water. How do you heat water? What sources do you use?
Answer:
They are heater, gas stove, fire wood, solar heater etc. We heat water with different heat energy giving sources.

3. Let us do this:

Question 1.
Do you find any difference in temperature of air in shadow and in the sun?
Measure temperature of air using a thermometer. What will you do to keep thermometer in close contact with air?
Record your observations in the following table.

Observation	Recorded Temperature
Air in the shade (at 12 noon)	32°C
Air in the sun (at 12 noon)	37°C
Morning (at 8 am)	28°C
Night (at 8 pm)	33°C

The thermometer is help up in the air. The mercury bulb of the thermometer is exposed to air. Therefore the mercury expansion is clearly seen. Also the reading is taken very easily.

Question 2.
What did you observe ? Is there any difference in temperature with variation of time or place ?
Answer:
Yes, during morning and night times temperature is low, whereas afternoon temperature is high.

Question 3.
Why do you use an umbrella in the hot sun during summer ?
Answer:
To protect our body from hot sun during summer. Umbrella stops the sun’s heat falling on our body.

Question 4.
Feel the body temperature of some of your friends by placing your hand on their forehead. Estimate the temperature and record it, in the table. Measure it now with clinical thermometer. Record your observations in table. Make sure that you have cleaned the thermometer before each measurement.
Answer:

Name of the Student	Estimated Temperature by touching	Temperature measured with clinical thermometer
Srinivas	99°F	98.7°F
Kiran	98.6°F	98.6°F
Vardhan	97°F	98.7°F
Mvthresh	100°F	98.8°F
Satya	98°F	98.4°F

Compare the values in the table after completion of recording.

1. What do you observe in the table ?
Answer: Temperature will differ from person to person.

2. Are the estimated temperature and measured temperature same ?
Answer: No.

3. Is the body temperature of every person 37°C (98.4°F) ?
Answer: No.

4. What is the average body temperature of your friends ?
Answer: 98.6°F.

5. Do you know ?
Thermister thermometer. It is available in market to measure the human body temperatures, particularly for infants and children. Can you guess why ?
Answer:

Clinical thermometer contains mercury which is a toxic substance and is very difficult to dispose of, if a thermometer breaks. So, it is harmful to measure temperature of infants and children.

TS 7th Class Science 5th Lesson Notes Heat-Measurement

• Heat energy : Heat is a form of energy that transfers among particles.
• Temperature : Temperature is a measure of the degree of hotness or coldness of an object.
• Thermometer : A thermometer is a device that measures temperature.
• Fahrenheit Scale : The scale of measuring temperature invented by Fahrenheit. In clinical thermometer, this scale starts from 95°F and ends at 110°F.
• Celsius Scale : The scale of measuring temperature invented by Celsius. In clinical thermometer, this scale starts from 35°C and ends at 45°C.
• Clinical thermometer : Doctors use a clinical thermometer to measure the human body temperature.
• Expansion : It is a phenomenon which is related to the working of clinical thermometer.
  (or)
  It is a phenomenon where matter increases its volume on constant heating.
• The energy which makes an object appear hot or cold is called heat.
• Heatflows front an object at higher temperature to another at liver temperature.
• Different kinds of energies like mechanical, chemical, solar energies are being converted to heat. In the same way, heat energy can be converted into other forms of energy.
• We use thermometers to measure temperature.
• Mercury and alcohol are used as thermometer liquids in thermometers.
• Thermometer is based on the fact that matter expands on heating.
• The melting point of ice is 0°C and boiling point of water is 100°C.
• First thermometer was invented by Galileo in 1593 AD.
• The normal temperature of human body is 36.9° C/37°C (98.4°F/ 98.6°F)
• The maximum and minimum temperatures of a day are measured by Six’s maximum minimum thermometer.
• Some other types of thermometers are thermister thermometer, digital thermometer.
• Relation between Celsius temperature and Fahrenheit temperature:
  \(\frac{C}{F}=\frac{F-32}{9}\)

TS Board Telangana SCERT Class 7 Science Solutions 4th Lesson Food Components Textbook Questions and Answers.

TS 7th Class Science 4th Lesson Questions and Answers Telangana – Lesson Motion and Time

Question 1.
State whether the following statements are ‘flue or False. Rewrite the wrong statements correctly.
a. A body can be at rest and in motion at the same time in relation to the same set of surroundings.
b. A passenger flying in an aeroplane is at rest with respect to the airport and moving with respect to other passengers.
c. The wheels of a train are in rotatory motion as well as in translatory motion when they move.
Answer:
a. False – A body may be at rest and in motion at the same time in relation to the different set of surroundings.
b. False – A passenger flying in an aeroplane is at rest with respect to other passengers and moving with respect to the airport.
c. True – Moving of train is translatory motion. Moving of wheels is rotatory motion.

Question 2.
John tied a stone to a string and whirled it around. What type of motion do you find there?
Answer:
Rotatory motion.

Question 3.
What is common to the following ? Motion of the propeller of a flying helicopter, the minute hand of a watch, the tape of a cassette recorder.
a) All are examples of translatory motion.
b) All are examples of oscillatory motion.
c) All are examples of rotatory motion.
d) All are examples of periodic motion.
Answer:
(c) All are examples of rotatory motion.

Question 4.
Which of the following is not an oscillatory motion?
a) Motion of the hammer of an electric bell.
b) Motion of your hands while running.
c) Motion of a child on a see-saw.
d) Motion of a horse pulling a cart.
Answer:
(d) Motion of a horse pulling a cart.

Question 5.
Arun completed a 100 meter race in 1 6s, while Karthik finished it in 13s. Who ran faster?
Answer:
Karthik is faster. He finished the same distance in less time.

Question 6.
I. A train runs from New Delhi to Hyderabad. It covers first distance of 420 km in 7 hrs, and next distance of 360 km in 6 hrs.
II. Gopi takes part in a car race. He drives a distance of 70 km each in the first, second and third hours. Which of the following statements is true.
a) I is an example of uniform motion and II an example of non-uniform motion.
b) I is an example of non-uniform motion and II an example of uniform motion.
c) I and II are examples of uniform motion.
d) I and II are examples of non-uniform motion.
Answer:
(c) I and II are examples of uniform motion.

Question 7.
Write the motion of different parts of a bicycle while it is in motion.
a. the wheel
b. the cycle chain
c. the pedal with its arms.
d. the movement of the pedalling feet
e. the movement of the rider along with the bicycle.
Answer:
a. Rotatory motion
b. Curvilinear motion
c. Translatory and rotatory motion
d. Rotatory motion
e. Linear motion

Question 8.
Which of the following statements is correct?
a. The basic unit of time is second.
b. Every objects motion is uniform.
c. Two cars move for 5 minutes and 2 minutes respectively. The second car is faster because it takes less time for the same distance.
d. The speed of a car is expressed in km/h.
Answer:
a. correct
b. wrong
c. correct
d. correct

Question 9.
The basic unit of speed in S.l. system.
a) km/mm
b) m/mm
c) km/h
d) m/s
Answer:
(d) m/s

Question 10.
The correct relation between speed, distance and time is
a) time = distance / speed
b) speed = time / distance
c) speed = distance / time
d) distance = speed / time
Answer:
(c) speed = distance/time.

Question 11.
The distance between two stations is 240 km. A train takes 4 hrs to cover this distance. Calculate the speed of the train.
Answer:
distance travelled = 240 km
time taken = 4 hrs

Question 12.
A train travels at a speed of 180 km/h. How far will it travel in 4 hours?
Answer:
Speed = 180 km/h.
time taken = 4 hrs.
\(\begin{aligned}
& \text { Speed }=\frac{\text { distance travelled }}{\text { time taken }} \\
& \frac{180}{1}=\frac{\text { distance travelled }}{4}
\end{aligned}\)
Distance travelled = 4 x 180 = 720 km.

Question 13.
When do you say an object is in rotatory motion.
Answer:
Motion of all particles of a moving body follow a circular path with respect to a fixed centre or axis of rotation. Then the body is said to be in rotatory motion.

Question 14.
Can an object possess translatory and rotatory motions at the same time? Give an example.
Answer:
An object can possess translatory and rotatory motions at the same time.
Eg: Motion of a rider on the bicycle is translatory and motion of wheels of the bicycle is rotatory.

Question 15.
Make a collection of action pictures showing living and non-living things in motion. Paste them neatly in a scrap book. Under each picture, write the type of motion the picture shows.
Answer:

Flying bird – L – Linear
Running cheetah – L – Linear
Columbus in exhibiton – NL – Oscillatory
Revolution of earth = NL -Rotatory

Question 16.
In a sewing machine used by tailors, mention the type of motion of sewing machine’s parts when it runs.
a. The wheel
b. The needle
c. The cloth
Answer:
a. Rotatory motion
b. Oscillatory motion
c. Linear motion

Question 17.
Gather the information about the apparatus used to measure time in olden days.
Answer:

In olden days, the instruments used to measure time are –

• sand clock
• water clock
• clock candles
• sundial
• pendulum clock.

In Text Questions And Answers

1. Let us do – 1

Observing motion of the car.

Look at the pictures. State which of the following statements are true.
Answer:
1. The distance between the driver and the car changes. (False)
2. The distance between the car and gate of the house is changed. (True)
3. There is no change in the position of gate of the house with respect to its surroundings. (True)
4. There are no changes in the position of the car with respect to its surroundings. (False)

2. Let us do – 2

Observing certain motions.

Observe the following pictures and answer the given blanks.
Answer:
1. The girl on the swing is ……………… with respect to the seat of the swing.
She is ……………… with respect to the garden. (at rest, moving)

2. The girl on the bicycle is ……………… with respect to the road.
She is at ……………… with respect to the bicycle. (moving, rest)

3. Let us do – 3.

Observing time and distance values.

Observe the following tables, showing distances travelled by two different cars for different intervals of time.

Time in Seconds	Distance Travelled
0 10 20 30 40	0m 150m 300 m 450 m 600 m

Car – A

Time in Seconds	Distance Travelled
0 10 20 30 40	0m 50 m 90 m 180 in 230 m

Car – B

1. Which car has travelled equal distances in equal intervals of time?
Answer:
Car-A

2. Which car has travelled unequal distances in equal intervals of time?
Answer:
Car – B

Let us do – 4.

Identifying Uniform and Non-Uniform Motion.
Identify uniform and non-uniform motions among the following examples and mark Uniform as (U) and Non Uniform as (NU).
Answer:
1. Movement of hands of a clock. (U)
2. A boy cycling in a crowded place. (NU)
3. Movement of a housefly. (NU)
4. The fan in an air cooler running at fixed speed. (U)
5. A train entering into a railway station. (NU)
6. Kite in the air. (NU)
7. Rotation of Earth. (U)

4. Look at the following picture.

The bus moved from point ‘A’ to ‘B’ in a certain interval of time.

Think and answer the following questions.

1. Do all the parts of bus (like wheels, head lights, windows etc.) move along from point ‘A’ to ‘B’?
Answer: Yes.

2. Is the direction of motion of bus along straight line or curved line?
Answer: Straight line.

3. Can you give some more examples of motion in which all points of moving body move in the same direction as that of the body?
Answer: Moving car, aeroplane, boat.

Let us do – 5:

Observing the path of the motion.

Observe the following table, and state the paths of motion for each case by putting (✓) mark in the relevant column.

6. Let us do – 6 :

Identifying types of motion.

We notice everyday some motions which are rectilinear and curvilinear at a time. Some examples of motions are given below. Label them as Rectilinear (R) or Curvilinear (C) or Rectilinear and curvilinear (RC) motions.
Answer:
1. Seconds hand of a watch (C)
2. Movement of a train on track. (R)
3. Movement of a tape in a tape recorder. (RC)
4. Movement of a needle in a speedometer of car. (C)
5. Movement of a bus on hill station road. (RC)
6. Motion of coins on a carrom board. (R)
7. Motion of the ball in pin board. (RC)
8. Motion of a mango falling from tree. (R)

7. Let us do – 7:

Observe the following diagrams

1. What similarity do you find in all the motions?
2. What is the path of motion of each particle of the body that moves?
3. Is there any change in the position of a body while it is in motion?
Answer:

1. All are in rotatory motion.
2. Circular path of motion.
3. No change.

8. Let us do – 8.

Observe the following motions of objects, state whether they are in rotatory motion. Draw a line showing axis of rotation using pencil as shown in fig-1.

Answer:

9. Let us do – 9

See the picture below. A girl took a tennis ball and kept it on the table. She pushed the ball with her fingers.
A. What will you observe if you do the same as the girl did?
B. Is it in Rotatory motion or in Translatory motion?
Answer:

• When the ball is pushed on the surface of a table, it moves from one end to the other end and all the particles of the ball also move along the direction of motion of the ball.
• Hence the ball is in translatory motion

B. Each particle of the ball moves in a circular path about a particular line; when the ball rolls on the surface. Therefore, it is in rotatory motion. Thus, in the given example, the ball shows both translatory and rotatory motion.

10. Let us do – 10:

Observe following motions of bodies and label them as Rotatory (R), Translatory (T), Translatory and Rotatory (TR)

11. Let us do – 11 :

Identify oscillatory motion among the following and put (✓) mark in the brackets given.
Answer:
1. A spinning top ( )
2. Bullet, fired from a gun ( )
3. Typewriter key ( ✓)
4. Motion of a potters wheel. ( )
5. Motion of a vibrating sitar string. ( ✓ )
6. Motion of a car taking a turn while moving. ( )
7. Ringingofa bell. ( ✓ )
8. A bouncing ball. ( ✓ )

12. Let us do – 12 :

Comparing the motion of objects.

Observe following pairs of objects that are in motion. Compare their motions and decide which move slower and which move faster. Mark (✓) in relevant box. How can you decide whether the motion of a body is slow or fast?
Answer:

13. Let us do: 13 :

Estimating time.

Ravi and Sathish started for school at 8.00 a.m. from their houses which are side by side. Ravi started on a bicycle and Sathish on foot.
i. Who will reach the school first? How much earlier will he be compared to the other?
ii. How do you measure early’ or ‘late’ arrival at school?
Answer:
i. Ravi will reach the school first. We need to measure the time taken by both Ravi and Sathish to answer second question.
ii. Easy or late can be measured by using watches, clocks etc.

Let us do – 14 :

Take a cell phone. Go to setting and open stop clock option. If you are not able to do this take help from your friend or teacher. Measure the time taken for the events mentioned in the table.
Answer:
Units of time:

Event	Duration of Time
Ringing of long bell in the school.	18s
Completion of prayer song.	55s
Running 200m by your friend in the school ground.	42s
Completion of pledge during school assembly.	40s

TS 7th Class Science 4th Lesson Notes Motion and Time

• Motion : Motion is a common experience in our life.
• Rest : An object is said to be at rest if there is no change in its position with respect to its surroundings in a given time.
• Translatory motion : If all parts of a moving body move in the direction of motion, then the motion is said to be translatory motion.
• Rotatory motion : Rotatory motion means motion of all particles of moving body follow a circular path with respect to a fixed centre or axis of rotation.
• Oscillatory motion : The ‘to’ and ‘fro’ motion of an object about a fixed point always following the same path is called oscillatory motion.
• Axis of rotation : The imaginary line passing through the fixed point is called axis of rotation.
• Average Speed:
  
• Speed : Speed of an object is the distance travelled by it in a unit time
  
• An object is said to be in motion ¡fit changes its position with respect to its surroundings in a given time.
• A body may be at rest with respect to one set of surroundings and at the same time, it may be in motion with respect to another set of surroundings. Thus, motion is relative to the observer.
• If a body covers equal distances in equal intervals of time, it is said to be in uniform motion.
• Ifa body covers unequal distances in equal intervals of time, it is said to be in non-uniform motion.
• There are three types of motions, namely translatory motion, rotatory motion and oscillatory motion.
• If a body in translatory motion moves along a straight line, then motion is called rectilinear motion.
• If a body in translatory motion moves along a curved path, then the motion is called curvilinear motion.
• We measure time by using different instruments like electronic clocks, digital clocks etc.
• Stop clocks are used to measure time interval between occurrence of events accurately.
• The basic unit of time is second(s), larger units of time are minutes min) and hours (h,).
• Speedometer helps us to know the speed of a vehicle.
• Unit of speed in SI system is meter/second.
• The distance travelled by an object in a given interval of tune can help us to decide which one is faster and which one is slower.
• 1 km/h =\(\frac{5}{18}\)m/s. 1 m/s \(\frac{18}{5}\) = km/h